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https://github.com/edk2-porting/linux-next.git
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093f38a2c1
fuse_simple_request() is converted to return length of last (instead of single) out arg, since FUSE_IOCTL_OUT has two out args, the second of which is variable length. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2338 lines
53 KiB
C
2338 lines
53 KiB
C
/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
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This program can be distributed under the terms of the GNU GPL.
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See the file COPYING.
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*/
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#include "fuse_i.h"
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/poll.h>
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#include <linux/sched/signal.h>
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#include <linux/uio.h>
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#include <linux/miscdevice.h>
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#include <linux/pagemap.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/pipe_fs_i.h>
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#include <linux/swap.h>
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#include <linux/splice.h>
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#include <linux/sched.h>
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MODULE_ALIAS_MISCDEV(FUSE_MINOR);
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MODULE_ALIAS("devname:fuse");
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/* Ordinary requests have even IDs, while interrupts IDs are odd */
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#define FUSE_INT_REQ_BIT (1ULL << 0)
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#define FUSE_REQ_ID_STEP (1ULL << 1)
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static struct kmem_cache *fuse_req_cachep;
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static struct fuse_dev *fuse_get_dev(struct file *file)
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{
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/*
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* Lockless access is OK, because file->private data is set
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* once during mount and is valid until the file is released.
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*/
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return READ_ONCE(file->private_data);
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}
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static void fuse_request_init(struct fuse_req *req, struct page **pages,
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struct fuse_page_desc *page_descs,
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unsigned npages)
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{
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INIT_LIST_HEAD(&req->list);
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INIT_LIST_HEAD(&req->intr_entry);
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init_waitqueue_head(&req->waitq);
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refcount_set(&req->count, 1);
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req->pages = pages;
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req->page_descs = page_descs;
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req->max_pages = npages;
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__set_bit(FR_PENDING, &req->flags);
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}
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static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
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{
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struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags);
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if (req) {
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struct page **pages = NULL;
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struct fuse_page_desc *page_descs = NULL;
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WARN_ON(npages > FUSE_MAX_MAX_PAGES);
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if (npages > FUSE_REQ_INLINE_PAGES) {
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pages = fuse_pages_alloc(npages, flags, &page_descs);
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if (!pages) {
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kmem_cache_free(fuse_req_cachep, req);
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return NULL;
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}
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__set_bit(FR_ALLOC_PAGES, &req->flags);
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} else if (npages) {
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pages = req->inline_pages;
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page_descs = req->inline_page_descs;
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}
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fuse_request_init(req, pages, page_descs, npages);
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}
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return req;
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}
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struct fuse_req *fuse_request_alloc(unsigned npages)
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{
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return __fuse_request_alloc(npages, GFP_KERNEL);
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}
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EXPORT_SYMBOL_GPL(fuse_request_alloc);
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struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
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{
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return __fuse_request_alloc(npages, GFP_NOFS);
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}
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static void fuse_req_pages_free(struct fuse_req *req)
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{
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if (test_bit(FR_ALLOC_PAGES, &req->flags))
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kfree(req->pages);
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}
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bool fuse_req_realloc_pages(struct fuse_conn *fc, struct fuse_req *req,
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gfp_t flags)
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{
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struct page **pages;
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struct fuse_page_desc *page_descs;
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unsigned int npages = min_t(unsigned int,
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max_t(unsigned int, req->max_pages * 2,
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FUSE_DEFAULT_MAX_PAGES_PER_REQ),
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fc->max_pages);
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WARN_ON(npages <= req->max_pages);
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pages = fuse_pages_alloc(npages, flags, &page_descs);
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if (!pages)
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return false;
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memcpy(pages, req->pages, sizeof(struct page *) * req->max_pages);
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memcpy(page_descs, req->page_descs,
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sizeof(struct fuse_page_desc) * req->max_pages);
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fuse_req_pages_free(req);
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__set_bit(FR_ALLOC_PAGES, &req->flags);
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req->pages = pages;
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req->page_descs = page_descs;
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req->max_pages = npages;
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return true;
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}
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void fuse_request_free(struct fuse_req *req)
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{
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fuse_req_pages_free(req);
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kmem_cache_free(fuse_req_cachep, req);
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}
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void __fuse_get_request(struct fuse_req *req)
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{
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refcount_inc(&req->count);
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}
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/* Must be called with > 1 refcount */
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static void __fuse_put_request(struct fuse_req *req)
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{
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refcount_dec(&req->count);
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}
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void fuse_set_initialized(struct fuse_conn *fc)
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{
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/* Make sure stores before this are seen on another CPU */
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smp_wmb();
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fc->initialized = 1;
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}
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static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
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{
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return !fc->initialized || (for_background && fc->blocked);
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}
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static void fuse_drop_waiting(struct fuse_conn *fc)
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{
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/*
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* lockess check of fc->connected is okay, because atomic_dec_and_test()
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* provides a memory barrier mached with the one in fuse_wait_aborted()
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* to ensure no wake-up is missed.
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*/
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if (atomic_dec_and_test(&fc->num_waiting) &&
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!READ_ONCE(fc->connected)) {
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/* wake up aborters */
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wake_up_all(&fc->blocked_waitq);
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}
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}
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static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
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bool for_background)
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{
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struct fuse_req *req;
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int err;
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atomic_inc(&fc->num_waiting);
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if (fuse_block_alloc(fc, for_background)) {
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err = -EINTR;
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if (wait_event_killable_exclusive(fc->blocked_waitq,
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!fuse_block_alloc(fc, for_background)))
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goto out;
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}
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/* Matches smp_wmb() in fuse_set_initialized() */
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smp_rmb();
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err = -ENOTCONN;
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if (!fc->connected)
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goto out;
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err = -ECONNREFUSED;
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if (fc->conn_error)
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goto out;
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req = fuse_request_alloc(npages);
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err = -ENOMEM;
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if (!req) {
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if (for_background)
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wake_up(&fc->blocked_waitq);
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goto out;
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}
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req->in.h.uid = from_kuid(fc->user_ns, current_fsuid());
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req->in.h.gid = from_kgid(fc->user_ns, current_fsgid());
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req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
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__set_bit(FR_WAITING, &req->flags);
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if (for_background)
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__set_bit(FR_BACKGROUND, &req->flags);
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if (unlikely(req->in.h.uid == ((uid_t)-1) ||
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req->in.h.gid == ((gid_t)-1))) {
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fuse_put_request(fc, req);
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return ERR_PTR(-EOVERFLOW);
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}
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return req;
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out:
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fuse_drop_waiting(fc);
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return ERR_PTR(err);
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}
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struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
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{
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return __fuse_get_req(fc, npages, false);
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}
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EXPORT_SYMBOL_GPL(fuse_get_req);
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struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
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unsigned npages)
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{
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return __fuse_get_req(fc, npages, true);
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}
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EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
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void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
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{
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if (refcount_dec_and_test(&req->count)) {
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if (test_bit(FR_BACKGROUND, &req->flags)) {
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/*
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* We get here in the unlikely case that a background
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* request was allocated but not sent
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*/
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spin_lock(&fc->bg_lock);
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if (!fc->blocked)
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wake_up(&fc->blocked_waitq);
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spin_unlock(&fc->bg_lock);
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}
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if (test_bit(FR_WAITING, &req->flags)) {
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__clear_bit(FR_WAITING, &req->flags);
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fuse_drop_waiting(fc);
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}
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fuse_request_free(req);
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}
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}
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EXPORT_SYMBOL_GPL(fuse_put_request);
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static unsigned len_args(unsigned numargs, struct fuse_arg *args)
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{
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unsigned nbytes = 0;
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unsigned i;
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for (i = 0; i < numargs; i++)
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nbytes += args[i].size;
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return nbytes;
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}
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static u64 fuse_get_unique(struct fuse_iqueue *fiq)
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{
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fiq->reqctr += FUSE_REQ_ID_STEP;
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return fiq->reqctr;
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}
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static unsigned int fuse_req_hash(u64 unique)
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{
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return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS);
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}
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static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
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{
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req->in.h.len = sizeof(struct fuse_in_header) +
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len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
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list_add_tail(&req->list, &fiq->pending);
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wake_up(&fiq->waitq);
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kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
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}
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void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
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u64 nodeid, u64 nlookup)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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forget->forget_one.nodeid = nodeid;
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forget->forget_one.nlookup = nlookup;
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spin_lock(&fiq->lock);
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if (fiq->connected) {
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fiq->forget_list_tail->next = forget;
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fiq->forget_list_tail = forget;
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wake_up(&fiq->waitq);
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kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
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} else {
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kfree(forget);
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}
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spin_unlock(&fiq->lock);
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}
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static void flush_bg_queue(struct fuse_conn *fc)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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while (fc->active_background < fc->max_background &&
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!list_empty(&fc->bg_queue)) {
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struct fuse_req *req;
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req = list_first_entry(&fc->bg_queue, struct fuse_req, list);
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list_del(&req->list);
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fc->active_background++;
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spin_lock(&fiq->lock);
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req->in.h.unique = fuse_get_unique(fiq);
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queue_request(fiq, req);
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spin_unlock(&fiq->lock);
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}
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}
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/*
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* This function is called when a request is finished. Either a reply
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* has arrived or it was aborted (and not yet sent) or some error
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* occurred during communication with userspace, or the device file
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* was closed. The requester thread is woken up (if still waiting),
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* the 'end' callback is called if given, else the reference to the
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* request is released
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*/
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static void request_end(struct fuse_conn *fc, struct fuse_req *req)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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if (test_and_set_bit(FR_FINISHED, &req->flags))
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goto put_request;
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/*
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* test_and_set_bit() implies smp_mb() between bit
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* changing and below intr_entry check. Pairs with
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* smp_mb() from queue_interrupt().
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*/
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if (!list_empty(&req->intr_entry)) {
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spin_lock(&fiq->lock);
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list_del_init(&req->intr_entry);
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spin_unlock(&fiq->lock);
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}
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WARN_ON(test_bit(FR_PENDING, &req->flags));
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WARN_ON(test_bit(FR_SENT, &req->flags));
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if (test_bit(FR_BACKGROUND, &req->flags)) {
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spin_lock(&fc->bg_lock);
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clear_bit(FR_BACKGROUND, &req->flags);
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if (fc->num_background == fc->max_background) {
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fc->blocked = 0;
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wake_up(&fc->blocked_waitq);
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} else if (!fc->blocked) {
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/*
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* Wake up next waiter, if any. It's okay to use
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* waitqueue_active(), as we've already synced up
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* fc->blocked with waiters with the wake_up() call
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* above.
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*/
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if (waitqueue_active(&fc->blocked_waitq))
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wake_up(&fc->blocked_waitq);
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}
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if (fc->num_background == fc->congestion_threshold && fc->sb) {
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clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
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clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
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}
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fc->num_background--;
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fc->active_background--;
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flush_bg_queue(fc);
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spin_unlock(&fc->bg_lock);
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} else {
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/* Wake up waiter sleeping in request_wait_answer() */
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wake_up(&req->waitq);
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}
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if (req->end)
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req->end(fc, req);
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put_request:
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fuse_put_request(fc, req);
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}
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static int queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
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{
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spin_lock(&fiq->lock);
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/* Check for we've sent request to interrupt this req */
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if (unlikely(!test_bit(FR_INTERRUPTED, &req->flags))) {
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spin_unlock(&fiq->lock);
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return -EINVAL;
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}
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if (list_empty(&req->intr_entry)) {
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list_add_tail(&req->intr_entry, &fiq->interrupts);
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/*
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* Pairs with smp_mb() implied by test_and_set_bit()
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* from request_end().
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*/
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smp_mb();
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if (test_bit(FR_FINISHED, &req->flags)) {
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list_del_init(&req->intr_entry);
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spin_unlock(&fiq->lock);
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return 0;
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}
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wake_up(&fiq->waitq);
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kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
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}
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spin_unlock(&fiq->lock);
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return 0;
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}
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static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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int err;
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if (!fc->no_interrupt) {
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/* Any signal may interrupt this */
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err = wait_event_interruptible(req->waitq,
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test_bit(FR_FINISHED, &req->flags));
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if (!err)
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return;
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set_bit(FR_INTERRUPTED, &req->flags);
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/* matches barrier in fuse_dev_do_read() */
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smp_mb__after_atomic();
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if (test_bit(FR_SENT, &req->flags))
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queue_interrupt(fiq, req);
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}
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if (!test_bit(FR_FORCE, &req->flags)) {
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/* Only fatal signals may interrupt this */
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err = wait_event_killable(req->waitq,
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test_bit(FR_FINISHED, &req->flags));
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if (!err)
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return;
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spin_lock(&fiq->lock);
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/* Request is not yet in userspace, bail out */
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if (test_bit(FR_PENDING, &req->flags)) {
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list_del(&req->list);
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spin_unlock(&fiq->lock);
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__fuse_put_request(req);
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req->out.h.error = -EINTR;
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return;
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}
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spin_unlock(&fiq->lock);
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}
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/*
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* Either request is already in userspace, or it was forced.
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* Wait it out.
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*/
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wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
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}
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static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
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spin_lock(&fiq->lock);
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if (!fiq->connected) {
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spin_unlock(&fiq->lock);
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req->out.h.error = -ENOTCONN;
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} else {
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req->in.h.unique = fuse_get_unique(fiq);
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queue_request(fiq, req);
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/* acquire extra reference, since request is still needed
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after request_end() */
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__fuse_get_request(req);
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spin_unlock(&fiq->lock);
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request_wait_answer(fc, req);
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/* Pairs with smp_wmb() in request_end() */
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smp_rmb();
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}
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}
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void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
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{
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__set_bit(FR_ISREPLY, &req->flags);
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if (!test_bit(FR_WAITING, &req->flags)) {
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__set_bit(FR_WAITING, &req->flags);
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atomic_inc(&fc->num_waiting);
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}
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__fuse_request_send(fc, req);
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}
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EXPORT_SYMBOL_GPL(fuse_request_send);
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static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
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{
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if (fc->minor < 4 && args->opcode == FUSE_STATFS)
|
|
args->out_args[0].size = FUSE_COMPAT_STATFS_SIZE;
|
|
|
|
if (fc->minor < 9) {
|
|
switch (args->opcode) {
|
|
case FUSE_LOOKUP:
|
|
case FUSE_CREATE:
|
|
case FUSE_MKNOD:
|
|
case FUSE_MKDIR:
|
|
case FUSE_SYMLINK:
|
|
case FUSE_LINK:
|
|
args->out_args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
|
|
break;
|
|
case FUSE_GETATTR:
|
|
case FUSE_SETATTR:
|
|
args->out_args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
|
|
break;
|
|
}
|
|
}
|
|
if (fc->minor < 12) {
|
|
switch (args->opcode) {
|
|
case FUSE_CREATE:
|
|
args->in_args[0].size = sizeof(struct fuse_open_in);
|
|
break;
|
|
case FUSE_MKNOD:
|
|
args->in_args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void fuse_force_creds(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());
|
|
req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());
|
|
req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
|
|
}
|
|
|
|
void fuse_args_to_req(struct fuse_req *req, struct fuse_args *args)
|
|
{
|
|
struct fuse_args_pages *ap = container_of(args, typeof(*ap), args);
|
|
|
|
req->in.h.opcode = args->opcode;
|
|
req->in.h.nodeid = args->nodeid;
|
|
req->in.numargs = args->in_numargs;
|
|
memcpy(req->in.args, args->in_args,
|
|
args->in_numargs * sizeof(struct fuse_in_arg));
|
|
req->out.argvar = args->out_argvar;
|
|
req->out.numargs = args->out_numargs;
|
|
memcpy(req->out.args, args->out_args,
|
|
args->out_numargs * sizeof(struct fuse_arg));
|
|
|
|
if (args->in_pages || args->out_pages) {
|
|
req->in.argpages = args->in_pages;
|
|
req->out.argpages = args->out_pages;
|
|
req->out.page_zeroing = args->page_zeroing;
|
|
req->out.page_replace = args->page_replace;
|
|
|
|
req->pages = ap->pages;
|
|
req->page_descs = ap->descs;
|
|
req->num_pages = ap->num_pages;
|
|
}
|
|
|
|
}
|
|
|
|
ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
|
|
{
|
|
struct fuse_req *req;
|
|
ssize_t ret;
|
|
|
|
if (args->force) {
|
|
atomic_inc(&fc->num_waiting);
|
|
req = __fuse_request_alloc(0, GFP_KERNEL | __GFP_NOFAIL);
|
|
|
|
if (!args->nocreds)
|
|
fuse_force_creds(fc, req);
|
|
|
|
__set_bit(FR_WAITING, &req->flags);
|
|
__set_bit(FR_FORCE, &req->flags);
|
|
} else {
|
|
WARN_ON(args->nocreds);
|
|
req = fuse_get_req(fc, 0);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
}
|
|
|
|
/* Needs to be done after fuse_get_req() so that fc->minor is valid */
|
|
fuse_adjust_compat(fc, args);
|
|
fuse_args_to_req(req, args);
|
|
|
|
if (!args->noreply)
|
|
__set_bit(FR_ISREPLY, &req->flags);
|
|
__fuse_request_send(fc, req);
|
|
ret = req->out.h.error;
|
|
if (!ret && args->out_argvar) {
|
|
BUG_ON(args->out_numargs == 0);
|
|
ret = req->out.args[args->out_numargs - 1].size;
|
|
}
|
|
fuse_put_request(fc, req);
|
|
|
|
return ret;
|
|
}
|
|
|
|
bool fuse_request_queue_background(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
bool queued = false;
|
|
|
|
WARN_ON(!test_bit(FR_BACKGROUND, &req->flags));
|
|
if (!test_bit(FR_WAITING, &req->flags)) {
|
|
__set_bit(FR_WAITING, &req->flags);
|
|
atomic_inc(&fc->num_waiting);
|
|
}
|
|
__set_bit(FR_ISREPLY, &req->flags);
|
|
spin_lock(&fc->bg_lock);
|
|
if (likely(fc->connected)) {
|
|
fc->num_background++;
|
|
if (fc->num_background == fc->max_background)
|
|
fc->blocked = 1;
|
|
if (fc->num_background == fc->congestion_threshold && fc->sb) {
|
|
set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
|
|
set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
|
|
}
|
|
list_add_tail(&req->list, &fc->bg_queue);
|
|
flush_bg_queue(fc);
|
|
queued = true;
|
|
}
|
|
spin_unlock(&fc->bg_lock);
|
|
|
|
return queued;
|
|
}
|
|
|
|
void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
WARN_ON(!req->end);
|
|
if (!fuse_request_queue_background(fc, req)) {
|
|
req->out.h.error = -ENOTCONN;
|
|
req->end(fc, req);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_request_send_background);
|
|
|
|
static int fuse_request_send_notify_reply(struct fuse_conn *fc,
|
|
struct fuse_req *req, u64 unique)
|
|
{
|
|
int err = -ENODEV;
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
|
|
__clear_bit(FR_ISREPLY, &req->flags);
|
|
req->in.h.unique = unique;
|
|
spin_lock(&fiq->lock);
|
|
if (fiq->connected) {
|
|
queue_request(fiq, req);
|
|
err = 0;
|
|
}
|
|
spin_unlock(&fiq->lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Lock the request. Up to the next unlock_request() there mustn't be
|
|
* anything that could cause a page-fault. If the request was already
|
|
* aborted bail out.
|
|
*/
|
|
static int lock_request(struct fuse_req *req)
|
|
{
|
|
int err = 0;
|
|
if (req) {
|
|
spin_lock(&req->waitq.lock);
|
|
if (test_bit(FR_ABORTED, &req->flags))
|
|
err = -ENOENT;
|
|
else
|
|
set_bit(FR_LOCKED, &req->flags);
|
|
spin_unlock(&req->waitq.lock);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Unlock request. If it was aborted while locked, caller is responsible
|
|
* for unlocking and ending the request.
|
|
*/
|
|
static int unlock_request(struct fuse_req *req)
|
|
{
|
|
int err = 0;
|
|
if (req) {
|
|
spin_lock(&req->waitq.lock);
|
|
if (test_bit(FR_ABORTED, &req->flags))
|
|
err = -ENOENT;
|
|
else
|
|
clear_bit(FR_LOCKED, &req->flags);
|
|
spin_unlock(&req->waitq.lock);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
struct fuse_copy_state {
|
|
int write;
|
|
struct fuse_req *req;
|
|
struct iov_iter *iter;
|
|
struct pipe_buffer *pipebufs;
|
|
struct pipe_buffer *currbuf;
|
|
struct pipe_inode_info *pipe;
|
|
unsigned long nr_segs;
|
|
struct page *pg;
|
|
unsigned len;
|
|
unsigned offset;
|
|
unsigned move_pages:1;
|
|
};
|
|
|
|
static void fuse_copy_init(struct fuse_copy_state *cs, int write,
|
|
struct iov_iter *iter)
|
|
{
|
|
memset(cs, 0, sizeof(*cs));
|
|
cs->write = write;
|
|
cs->iter = iter;
|
|
}
|
|
|
|
/* Unmap and put previous page of userspace buffer */
|
|
static void fuse_copy_finish(struct fuse_copy_state *cs)
|
|
{
|
|
if (cs->currbuf) {
|
|
struct pipe_buffer *buf = cs->currbuf;
|
|
|
|
if (cs->write)
|
|
buf->len = PAGE_SIZE - cs->len;
|
|
cs->currbuf = NULL;
|
|
} else if (cs->pg) {
|
|
if (cs->write) {
|
|
flush_dcache_page(cs->pg);
|
|
set_page_dirty_lock(cs->pg);
|
|
}
|
|
put_page(cs->pg);
|
|
}
|
|
cs->pg = NULL;
|
|
}
|
|
|
|
/*
|
|
* Get another pagefull of userspace buffer, and map it to kernel
|
|
* address space, and lock request
|
|
*/
|
|
static int fuse_copy_fill(struct fuse_copy_state *cs)
|
|
{
|
|
struct page *page;
|
|
int err;
|
|
|
|
err = unlock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_copy_finish(cs);
|
|
if (cs->pipebufs) {
|
|
struct pipe_buffer *buf = cs->pipebufs;
|
|
|
|
if (!cs->write) {
|
|
err = pipe_buf_confirm(cs->pipe, buf);
|
|
if (err)
|
|
return err;
|
|
|
|
BUG_ON(!cs->nr_segs);
|
|
cs->currbuf = buf;
|
|
cs->pg = buf->page;
|
|
cs->offset = buf->offset;
|
|
cs->len = buf->len;
|
|
cs->pipebufs++;
|
|
cs->nr_segs--;
|
|
} else {
|
|
if (cs->nr_segs == cs->pipe->buffers)
|
|
return -EIO;
|
|
|
|
page = alloc_page(GFP_HIGHUSER);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
buf->page = page;
|
|
buf->offset = 0;
|
|
buf->len = 0;
|
|
|
|
cs->currbuf = buf;
|
|
cs->pg = page;
|
|
cs->offset = 0;
|
|
cs->len = PAGE_SIZE;
|
|
cs->pipebufs++;
|
|
cs->nr_segs++;
|
|
}
|
|
} else {
|
|
size_t off;
|
|
err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
|
|
if (err < 0)
|
|
return err;
|
|
BUG_ON(!err);
|
|
cs->len = err;
|
|
cs->offset = off;
|
|
cs->pg = page;
|
|
iov_iter_advance(cs->iter, err);
|
|
}
|
|
|
|
return lock_request(cs->req);
|
|
}
|
|
|
|
/* Do as much copy to/from userspace buffer as we can */
|
|
static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
|
|
{
|
|
unsigned ncpy = min(*size, cs->len);
|
|
if (val) {
|
|
void *pgaddr = kmap_atomic(cs->pg);
|
|
void *buf = pgaddr + cs->offset;
|
|
|
|
if (cs->write)
|
|
memcpy(buf, *val, ncpy);
|
|
else
|
|
memcpy(*val, buf, ncpy);
|
|
|
|
kunmap_atomic(pgaddr);
|
|
*val += ncpy;
|
|
}
|
|
*size -= ncpy;
|
|
cs->len -= ncpy;
|
|
cs->offset += ncpy;
|
|
return ncpy;
|
|
}
|
|
|
|
static int fuse_check_page(struct page *page)
|
|
{
|
|
if (page_mapcount(page) ||
|
|
page->mapping != NULL ||
|
|
page_count(page) != 1 ||
|
|
(page->flags & PAGE_FLAGS_CHECK_AT_PREP &
|
|
~(1 << PG_locked |
|
|
1 << PG_referenced |
|
|
1 << PG_uptodate |
|
|
1 << PG_lru |
|
|
1 << PG_active |
|
|
1 << PG_reclaim))) {
|
|
pr_warn("trying to steal weird page\n");
|
|
pr_warn(" page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
|
|
{
|
|
int err;
|
|
struct page *oldpage = *pagep;
|
|
struct page *newpage;
|
|
struct pipe_buffer *buf = cs->pipebufs;
|
|
|
|
err = unlock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
err = pipe_buf_confirm(cs->pipe, buf);
|
|
if (err)
|
|
return err;
|
|
|
|
BUG_ON(!cs->nr_segs);
|
|
cs->currbuf = buf;
|
|
cs->len = buf->len;
|
|
cs->pipebufs++;
|
|
cs->nr_segs--;
|
|
|
|
if (cs->len != PAGE_SIZE)
|
|
goto out_fallback;
|
|
|
|
if (pipe_buf_steal(cs->pipe, buf) != 0)
|
|
goto out_fallback;
|
|
|
|
newpage = buf->page;
|
|
|
|
if (!PageUptodate(newpage))
|
|
SetPageUptodate(newpage);
|
|
|
|
ClearPageMappedToDisk(newpage);
|
|
|
|
if (fuse_check_page(newpage) != 0)
|
|
goto out_fallback_unlock;
|
|
|
|
/*
|
|
* This is a new and locked page, it shouldn't be mapped or
|
|
* have any special flags on it
|
|
*/
|
|
if (WARN_ON(page_mapped(oldpage)))
|
|
goto out_fallback_unlock;
|
|
if (WARN_ON(page_has_private(oldpage)))
|
|
goto out_fallback_unlock;
|
|
if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
|
|
goto out_fallback_unlock;
|
|
if (WARN_ON(PageMlocked(oldpage)))
|
|
goto out_fallback_unlock;
|
|
|
|
err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
|
|
if (err) {
|
|
unlock_page(newpage);
|
|
return err;
|
|
}
|
|
|
|
get_page(newpage);
|
|
|
|
if (!(buf->flags & PIPE_BUF_FLAG_LRU))
|
|
lru_cache_add_file(newpage);
|
|
|
|
err = 0;
|
|
spin_lock(&cs->req->waitq.lock);
|
|
if (test_bit(FR_ABORTED, &cs->req->flags))
|
|
err = -ENOENT;
|
|
else
|
|
*pagep = newpage;
|
|
spin_unlock(&cs->req->waitq.lock);
|
|
|
|
if (err) {
|
|
unlock_page(newpage);
|
|
put_page(newpage);
|
|
return err;
|
|
}
|
|
|
|
unlock_page(oldpage);
|
|
put_page(oldpage);
|
|
cs->len = 0;
|
|
|
|
return 0;
|
|
|
|
out_fallback_unlock:
|
|
unlock_page(newpage);
|
|
out_fallback:
|
|
cs->pg = buf->page;
|
|
cs->offset = buf->offset;
|
|
|
|
err = lock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
|
|
unsigned offset, unsigned count)
|
|
{
|
|
struct pipe_buffer *buf;
|
|
int err;
|
|
|
|
if (cs->nr_segs == cs->pipe->buffers)
|
|
return -EIO;
|
|
|
|
err = unlock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
buf = cs->pipebufs;
|
|
get_page(page);
|
|
buf->page = page;
|
|
buf->offset = offset;
|
|
buf->len = count;
|
|
|
|
cs->pipebufs++;
|
|
cs->nr_segs++;
|
|
cs->len = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Copy a page in the request to/from the userspace buffer. Must be
|
|
* done atomically
|
|
*/
|
|
static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
|
|
unsigned offset, unsigned count, int zeroing)
|
|
{
|
|
int err;
|
|
struct page *page = *pagep;
|
|
|
|
if (page && zeroing && count < PAGE_SIZE)
|
|
clear_highpage(page);
|
|
|
|
while (count) {
|
|
if (cs->write && cs->pipebufs && page) {
|
|
return fuse_ref_page(cs, page, offset, count);
|
|
} else if (!cs->len) {
|
|
if (cs->move_pages && page &&
|
|
offset == 0 && count == PAGE_SIZE) {
|
|
err = fuse_try_move_page(cs, pagep);
|
|
if (err <= 0)
|
|
return err;
|
|
} else {
|
|
err = fuse_copy_fill(cs);
|
|
if (err)
|
|
return err;
|
|
}
|
|
}
|
|
if (page) {
|
|
void *mapaddr = kmap_atomic(page);
|
|
void *buf = mapaddr + offset;
|
|
offset += fuse_copy_do(cs, &buf, &count);
|
|
kunmap_atomic(mapaddr);
|
|
} else
|
|
offset += fuse_copy_do(cs, NULL, &count);
|
|
}
|
|
if (page && !cs->write)
|
|
flush_dcache_page(page);
|
|
return 0;
|
|
}
|
|
|
|
/* Copy pages in the request to/from userspace buffer */
|
|
static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
|
|
int zeroing)
|
|
{
|
|
unsigned i;
|
|
struct fuse_req *req = cs->req;
|
|
|
|
for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
|
|
int err;
|
|
unsigned offset = req->page_descs[i].offset;
|
|
unsigned count = min(nbytes, req->page_descs[i].length);
|
|
|
|
err = fuse_copy_page(cs, &req->pages[i], offset, count,
|
|
zeroing);
|
|
if (err)
|
|
return err;
|
|
|
|
nbytes -= count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Copy a single argument in the request to/from userspace buffer */
|
|
static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
|
|
{
|
|
while (size) {
|
|
if (!cs->len) {
|
|
int err = fuse_copy_fill(cs);
|
|
if (err)
|
|
return err;
|
|
}
|
|
fuse_copy_do(cs, &val, &size);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Copy request arguments to/from userspace buffer */
|
|
static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
|
|
unsigned argpages, struct fuse_arg *args,
|
|
int zeroing)
|
|
{
|
|
int err = 0;
|
|
unsigned i;
|
|
|
|
for (i = 0; !err && i < numargs; i++) {
|
|
struct fuse_arg *arg = &args[i];
|
|
if (i == numargs - 1 && argpages)
|
|
err = fuse_copy_pages(cs, arg->size, zeroing);
|
|
else
|
|
err = fuse_copy_one(cs, arg->value, arg->size);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int forget_pending(struct fuse_iqueue *fiq)
|
|
{
|
|
return fiq->forget_list_head.next != NULL;
|
|
}
|
|
|
|
static int request_pending(struct fuse_iqueue *fiq)
|
|
{
|
|
return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
|
|
forget_pending(fiq);
|
|
}
|
|
|
|
/*
|
|
* Transfer an interrupt request to userspace
|
|
*
|
|
* Unlike other requests this is assembled on demand, without a need
|
|
* to allocate a separate fuse_req structure.
|
|
*
|
|
* Called with fiq->lock held, releases it
|
|
*/
|
|
static int fuse_read_interrupt(struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs,
|
|
size_t nbytes, struct fuse_req *req)
|
|
__releases(fiq->lock)
|
|
{
|
|
struct fuse_in_header ih;
|
|
struct fuse_interrupt_in arg;
|
|
unsigned reqsize = sizeof(ih) + sizeof(arg);
|
|
int err;
|
|
|
|
list_del_init(&req->intr_entry);
|
|
memset(&ih, 0, sizeof(ih));
|
|
memset(&arg, 0, sizeof(arg));
|
|
ih.len = reqsize;
|
|
ih.opcode = FUSE_INTERRUPT;
|
|
ih.unique = (req->in.h.unique | FUSE_INT_REQ_BIT);
|
|
arg.unique = req->in.h.unique;
|
|
|
|
spin_unlock(&fiq->lock);
|
|
if (nbytes < reqsize)
|
|
return -EINVAL;
|
|
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih));
|
|
if (!err)
|
|
err = fuse_copy_one(cs, &arg, sizeof(arg));
|
|
fuse_copy_finish(cs);
|
|
|
|
return err ? err : reqsize;
|
|
}
|
|
|
|
static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
|
|
unsigned max,
|
|
unsigned *countp)
|
|
{
|
|
struct fuse_forget_link *head = fiq->forget_list_head.next;
|
|
struct fuse_forget_link **newhead = &head;
|
|
unsigned count;
|
|
|
|
for (count = 0; *newhead != NULL && count < max; count++)
|
|
newhead = &(*newhead)->next;
|
|
|
|
fiq->forget_list_head.next = *newhead;
|
|
*newhead = NULL;
|
|
if (fiq->forget_list_head.next == NULL)
|
|
fiq->forget_list_tail = &fiq->forget_list_head;
|
|
|
|
if (countp != NULL)
|
|
*countp = count;
|
|
|
|
return head;
|
|
}
|
|
|
|
static int fuse_read_single_forget(struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs,
|
|
size_t nbytes)
|
|
__releases(fiq->lock)
|
|
{
|
|
int err;
|
|
struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
|
|
struct fuse_forget_in arg = {
|
|
.nlookup = forget->forget_one.nlookup,
|
|
};
|
|
struct fuse_in_header ih = {
|
|
.opcode = FUSE_FORGET,
|
|
.nodeid = forget->forget_one.nodeid,
|
|
.unique = fuse_get_unique(fiq),
|
|
.len = sizeof(ih) + sizeof(arg),
|
|
};
|
|
|
|
spin_unlock(&fiq->lock);
|
|
kfree(forget);
|
|
if (nbytes < ih.len)
|
|
return -EINVAL;
|
|
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih));
|
|
if (!err)
|
|
err = fuse_copy_one(cs, &arg, sizeof(arg));
|
|
fuse_copy_finish(cs);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
return ih.len;
|
|
}
|
|
|
|
static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
__releases(fiq->lock)
|
|
{
|
|
int err;
|
|
unsigned max_forgets;
|
|
unsigned count;
|
|
struct fuse_forget_link *head;
|
|
struct fuse_batch_forget_in arg = { .count = 0 };
|
|
struct fuse_in_header ih = {
|
|
.opcode = FUSE_BATCH_FORGET,
|
|
.unique = fuse_get_unique(fiq),
|
|
.len = sizeof(ih) + sizeof(arg),
|
|
};
|
|
|
|
if (nbytes < ih.len) {
|
|
spin_unlock(&fiq->lock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
|
|
head = dequeue_forget(fiq, max_forgets, &count);
|
|
spin_unlock(&fiq->lock);
|
|
|
|
arg.count = count;
|
|
ih.len += count * sizeof(struct fuse_forget_one);
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih));
|
|
if (!err)
|
|
err = fuse_copy_one(cs, &arg, sizeof(arg));
|
|
|
|
while (head) {
|
|
struct fuse_forget_link *forget = head;
|
|
|
|
if (!err) {
|
|
err = fuse_copy_one(cs, &forget->forget_one,
|
|
sizeof(forget->forget_one));
|
|
}
|
|
head = forget->next;
|
|
kfree(forget);
|
|
}
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
return ih.len;
|
|
}
|
|
|
|
static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs,
|
|
size_t nbytes)
|
|
__releases(fiq->lock)
|
|
{
|
|
if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
|
|
return fuse_read_single_forget(fiq, cs, nbytes);
|
|
else
|
|
return fuse_read_batch_forget(fiq, cs, nbytes);
|
|
}
|
|
|
|
/*
|
|
* Read a single request into the userspace filesystem's buffer. This
|
|
* function waits until a request is available, then removes it from
|
|
* the pending list and copies request data to userspace buffer. If
|
|
* no reply is needed (FORGET) or request has been aborted or there
|
|
* was an error during the copying then it's finished by calling
|
|
* request_end(). Otherwise add it to the processing list, and set
|
|
* the 'sent' flag.
|
|
*/
|
|
static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
{
|
|
ssize_t err;
|
|
struct fuse_conn *fc = fud->fc;
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
struct fuse_req *req;
|
|
struct fuse_in *in;
|
|
unsigned reqsize;
|
|
unsigned int hash;
|
|
|
|
/*
|
|
* Require sane minimum read buffer - that has capacity for fixed part
|
|
* of any request header + negotiated max_write room for data.
|
|
*
|
|
* Historically libfuse reserves 4K for fixed header room, but e.g.
|
|
* GlusterFS reserves only 80 bytes
|
|
*
|
|
* = `sizeof(fuse_in_header) + sizeof(fuse_write_in)`
|
|
*
|
|
* which is the absolute minimum any sane filesystem should be using
|
|
* for header room.
|
|
*/
|
|
if (nbytes < max_t(size_t, FUSE_MIN_READ_BUFFER,
|
|
sizeof(struct fuse_in_header) +
|
|
sizeof(struct fuse_write_in) +
|
|
fc->max_write))
|
|
return -EINVAL;
|
|
|
|
restart:
|
|
for (;;) {
|
|
spin_lock(&fiq->lock);
|
|
if (!fiq->connected || request_pending(fiq))
|
|
break;
|
|
spin_unlock(&fiq->lock);
|
|
|
|
if (file->f_flags & O_NONBLOCK)
|
|
return -EAGAIN;
|
|
err = wait_event_interruptible_exclusive(fiq->waitq,
|
|
!fiq->connected || request_pending(fiq));
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (!fiq->connected) {
|
|
err = fc->aborted ? -ECONNABORTED : -ENODEV;
|
|
goto err_unlock;
|
|
}
|
|
|
|
if (!list_empty(&fiq->interrupts)) {
|
|
req = list_entry(fiq->interrupts.next, struct fuse_req,
|
|
intr_entry);
|
|
return fuse_read_interrupt(fiq, cs, nbytes, req);
|
|
}
|
|
|
|
if (forget_pending(fiq)) {
|
|
if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
|
|
return fuse_read_forget(fc, fiq, cs, nbytes);
|
|
|
|
if (fiq->forget_batch <= -8)
|
|
fiq->forget_batch = 16;
|
|
}
|
|
|
|
req = list_entry(fiq->pending.next, struct fuse_req, list);
|
|
clear_bit(FR_PENDING, &req->flags);
|
|
list_del_init(&req->list);
|
|
spin_unlock(&fiq->lock);
|
|
|
|
in = &req->in;
|
|
reqsize = in->h.len;
|
|
|
|
/* If request is too large, reply with an error and restart the read */
|
|
if (nbytes < reqsize) {
|
|
req->out.h.error = -EIO;
|
|
/* SETXATTR is special, since it may contain too large data */
|
|
if (in->h.opcode == FUSE_SETXATTR)
|
|
req->out.h.error = -E2BIG;
|
|
request_end(fc, req);
|
|
goto restart;
|
|
}
|
|
spin_lock(&fpq->lock);
|
|
list_add(&req->list, &fpq->io);
|
|
spin_unlock(&fpq->lock);
|
|
cs->req = req;
|
|
err = fuse_copy_one(cs, &in->h, sizeof(in->h));
|
|
if (!err)
|
|
err = fuse_copy_args(cs, in->numargs, in->argpages,
|
|
(struct fuse_arg *) in->args, 0);
|
|
fuse_copy_finish(cs);
|
|
spin_lock(&fpq->lock);
|
|
clear_bit(FR_LOCKED, &req->flags);
|
|
if (!fpq->connected) {
|
|
err = fc->aborted ? -ECONNABORTED : -ENODEV;
|
|
goto out_end;
|
|
}
|
|
if (err) {
|
|
req->out.h.error = -EIO;
|
|
goto out_end;
|
|
}
|
|
if (!test_bit(FR_ISREPLY, &req->flags)) {
|
|
err = reqsize;
|
|
goto out_end;
|
|
}
|
|
hash = fuse_req_hash(req->in.h.unique);
|
|
list_move_tail(&req->list, &fpq->processing[hash]);
|
|
__fuse_get_request(req);
|
|
set_bit(FR_SENT, &req->flags);
|
|
spin_unlock(&fpq->lock);
|
|
/* matches barrier in request_wait_answer() */
|
|
smp_mb__after_atomic();
|
|
if (test_bit(FR_INTERRUPTED, &req->flags))
|
|
queue_interrupt(fiq, req);
|
|
fuse_put_request(fc, req);
|
|
|
|
return reqsize;
|
|
|
|
out_end:
|
|
if (!test_bit(FR_PRIVATE, &req->flags))
|
|
list_del_init(&req->list);
|
|
spin_unlock(&fpq->lock);
|
|
request_end(fc, req);
|
|
return err;
|
|
|
|
err_unlock:
|
|
spin_unlock(&fiq->lock);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_dev_open(struct inode *inode, struct file *file)
|
|
{
|
|
/*
|
|
* The fuse device's file's private_data is used to hold
|
|
* the fuse_conn(ection) when it is mounted, and is used to
|
|
* keep track of whether the file has been mounted already.
|
|
*/
|
|
file->private_data = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
|
|
{
|
|
struct fuse_copy_state cs;
|
|
struct file *file = iocb->ki_filp;
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
if (!iter_is_iovec(to))
|
|
return -EINVAL;
|
|
|
|
fuse_copy_init(&cs, 1, to);
|
|
|
|
return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
|
|
}
|
|
|
|
static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
|
|
struct pipe_inode_info *pipe,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
int total, ret;
|
|
int page_nr = 0;
|
|
struct pipe_buffer *bufs;
|
|
struct fuse_copy_state cs;
|
|
struct fuse_dev *fud = fuse_get_dev(in);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
|
|
GFP_KERNEL);
|
|
if (!bufs)
|
|
return -ENOMEM;
|
|
|
|
fuse_copy_init(&cs, 1, NULL);
|
|
cs.pipebufs = bufs;
|
|
cs.pipe = pipe;
|
|
ret = fuse_dev_do_read(fud, in, &cs, len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
for (ret = total = 0; page_nr < cs.nr_segs; total += ret) {
|
|
/*
|
|
* Need to be careful about this. Having buf->ops in module
|
|
* code can Oops if the buffer persists after module unload.
|
|
*/
|
|
bufs[page_nr].ops = &nosteal_pipe_buf_ops;
|
|
bufs[page_nr].flags = 0;
|
|
ret = add_to_pipe(pipe, &bufs[page_nr++]);
|
|
if (unlikely(ret < 0))
|
|
break;
|
|
}
|
|
if (total)
|
|
ret = total;
|
|
out:
|
|
for (; page_nr < cs.nr_segs; page_nr++)
|
|
put_page(bufs[page_nr].page);
|
|
|
|
kvfree(bufs);
|
|
return ret;
|
|
}
|
|
|
|
static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_poll_wakeup_out outarg;
|
|
int err = -EINVAL;
|
|
|
|
if (size != sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
|
|
fuse_copy_finish(cs);
|
|
return fuse_notify_poll_wakeup(fc, &outarg);
|
|
|
|
err:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_inval_inode_out outarg;
|
|
int err = -EINVAL;
|
|
|
|
if (size != sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
fuse_copy_finish(cs);
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb) {
|
|
err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
|
|
outarg.off, outarg.len);
|
|
}
|
|
up_read(&fc->killsb);
|
|
return err;
|
|
|
|
err:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_inval_entry_out outarg;
|
|
int err = -ENOMEM;
|
|
char *buf;
|
|
struct qstr name;
|
|
|
|
buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
|
|
if (!buf)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size < sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
|
|
err = -ENAMETOOLONG;
|
|
if (outarg.namelen > FUSE_NAME_MAX)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size != sizeof(outarg) + outarg.namelen + 1)
|
|
goto err;
|
|
|
|
name.name = buf;
|
|
name.len = outarg.namelen;
|
|
err = fuse_copy_one(cs, buf, outarg.namelen + 1);
|
|
if (err)
|
|
goto err;
|
|
fuse_copy_finish(cs);
|
|
buf[outarg.namelen] = 0;
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb)
|
|
err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
|
|
up_read(&fc->killsb);
|
|
kfree(buf);
|
|
return err;
|
|
|
|
err:
|
|
kfree(buf);
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_delete_out outarg;
|
|
int err = -ENOMEM;
|
|
char *buf;
|
|
struct qstr name;
|
|
|
|
buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
|
|
if (!buf)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size < sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
|
|
err = -ENAMETOOLONG;
|
|
if (outarg.namelen > FUSE_NAME_MAX)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size != sizeof(outarg) + outarg.namelen + 1)
|
|
goto err;
|
|
|
|
name.name = buf;
|
|
name.len = outarg.namelen;
|
|
err = fuse_copy_one(cs, buf, outarg.namelen + 1);
|
|
if (err)
|
|
goto err;
|
|
fuse_copy_finish(cs);
|
|
buf[outarg.namelen] = 0;
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb)
|
|
err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
|
|
outarg.child, &name);
|
|
up_read(&fc->killsb);
|
|
kfree(buf);
|
|
return err;
|
|
|
|
err:
|
|
kfree(buf);
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_store_out outarg;
|
|
struct inode *inode;
|
|
struct address_space *mapping;
|
|
u64 nodeid;
|
|
int err;
|
|
pgoff_t index;
|
|
unsigned int offset;
|
|
unsigned int num;
|
|
loff_t file_size;
|
|
loff_t end;
|
|
|
|
err = -EINVAL;
|
|
if (size < sizeof(outarg))
|
|
goto out_finish;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto out_finish;
|
|
|
|
err = -EINVAL;
|
|
if (size - sizeof(outarg) != outarg.size)
|
|
goto out_finish;
|
|
|
|
nodeid = outarg.nodeid;
|
|
|
|
down_read(&fc->killsb);
|
|
|
|
err = -ENOENT;
|
|
if (!fc->sb)
|
|
goto out_up_killsb;
|
|
|
|
inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
|
|
if (!inode)
|
|
goto out_up_killsb;
|
|
|
|
mapping = inode->i_mapping;
|
|
index = outarg.offset >> PAGE_SHIFT;
|
|
offset = outarg.offset & ~PAGE_MASK;
|
|
file_size = i_size_read(inode);
|
|
end = outarg.offset + outarg.size;
|
|
if (end > file_size) {
|
|
file_size = end;
|
|
fuse_write_update_size(inode, file_size);
|
|
}
|
|
|
|
num = outarg.size;
|
|
while (num) {
|
|
struct page *page;
|
|
unsigned int this_num;
|
|
|
|
err = -ENOMEM;
|
|
page = find_or_create_page(mapping, index,
|
|
mapping_gfp_mask(mapping));
|
|
if (!page)
|
|
goto out_iput;
|
|
|
|
this_num = min_t(unsigned, num, PAGE_SIZE - offset);
|
|
err = fuse_copy_page(cs, &page, offset, this_num, 0);
|
|
if (!err && offset == 0 &&
|
|
(this_num == PAGE_SIZE || file_size == end))
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
put_page(page);
|
|
|
|
if (err)
|
|
goto out_iput;
|
|
|
|
num -= this_num;
|
|
offset = 0;
|
|
index++;
|
|
}
|
|
|
|
err = 0;
|
|
|
|
out_iput:
|
|
iput(inode);
|
|
out_up_killsb:
|
|
up_read(&fc->killsb);
|
|
out_finish:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
release_pages(req->pages, req->num_pages);
|
|
}
|
|
|
|
static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
|
|
struct fuse_notify_retrieve_out *outarg)
|
|
{
|
|
int err;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct fuse_req *req;
|
|
pgoff_t index;
|
|
loff_t file_size;
|
|
unsigned int num;
|
|
unsigned int offset;
|
|
size_t total_len = 0;
|
|
unsigned int num_pages;
|
|
|
|
offset = outarg->offset & ~PAGE_MASK;
|
|
file_size = i_size_read(inode);
|
|
|
|
num = min(outarg->size, fc->max_write);
|
|
if (outarg->offset > file_size)
|
|
num = 0;
|
|
else if (outarg->offset + num > file_size)
|
|
num = file_size - outarg->offset;
|
|
|
|
num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
num_pages = min(num_pages, fc->max_pages);
|
|
|
|
req = fuse_get_req(fc, num_pages);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
req->in.h.opcode = FUSE_NOTIFY_REPLY;
|
|
req->in.h.nodeid = outarg->nodeid;
|
|
req->in.numargs = 2;
|
|
req->in.argpages = 1;
|
|
req->end = fuse_retrieve_end;
|
|
|
|
index = outarg->offset >> PAGE_SHIFT;
|
|
|
|
while (num && req->num_pages < num_pages) {
|
|
struct page *page;
|
|
unsigned int this_num;
|
|
|
|
page = find_get_page(mapping, index);
|
|
if (!page)
|
|
break;
|
|
|
|
this_num = min_t(unsigned, num, PAGE_SIZE - offset);
|
|
req->pages[req->num_pages] = page;
|
|
req->page_descs[req->num_pages].offset = offset;
|
|
req->page_descs[req->num_pages].length = this_num;
|
|
req->num_pages++;
|
|
|
|
offset = 0;
|
|
num -= this_num;
|
|
total_len += this_num;
|
|
index++;
|
|
}
|
|
req->misc.retrieve_in.offset = outarg->offset;
|
|
req->misc.retrieve_in.size = total_len;
|
|
req->in.args[0].size = sizeof(req->misc.retrieve_in);
|
|
req->in.args[0].value = &req->misc.retrieve_in;
|
|
req->in.args[1].size = total_len;
|
|
|
|
err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
|
|
if (err) {
|
|
fuse_retrieve_end(fc, req);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_retrieve_out outarg;
|
|
struct inode *inode;
|
|
int err;
|
|
|
|
err = -EINVAL;
|
|
if (size != sizeof(outarg))
|
|
goto copy_finish;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto copy_finish;
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb) {
|
|
u64 nodeid = outarg.nodeid;
|
|
|
|
inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
|
|
if (inode) {
|
|
err = fuse_retrieve(fc, inode, &outarg);
|
|
iput(inode);
|
|
}
|
|
}
|
|
up_read(&fc->killsb);
|
|
|
|
return err;
|
|
|
|
copy_finish:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
|
|
unsigned int size, struct fuse_copy_state *cs)
|
|
{
|
|
/* Don't try to move pages (yet) */
|
|
cs->move_pages = 0;
|
|
|
|
switch (code) {
|
|
case FUSE_NOTIFY_POLL:
|
|
return fuse_notify_poll(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_INVAL_INODE:
|
|
return fuse_notify_inval_inode(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_INVAL_ENTRY:
|
|
return fuse_notify_inval_entry(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_STORE:
|
|
return fuse_notify_store(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_RETRIEVE:
|
|
return fuse_notify_retrieve(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_DELETE:
|
|
return fuse_notify_delete(fc, size, cs);
|
|
|
|
default:
|
|
fuse_copy_finish(cs);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Look up request on processing list by unique ID */
|
|
static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
|
|
{
|
|
unsigned int hash = fuse_req_hash(unique);
|
|
struct fuse_req *req;
|
|
|
|
list_for_each_entry(req, &fpq->processing[hash], list) {
|
|
if (req->in.h.unique == unique)
|
|
return req;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
|
|
unsigned nbytes)
|
|
{
|
|
unsigned reqsize = sizeof(struct fuse_out_header);
|
|
|
|
if (out->h.error)
|
|
return nbytes != reqsize ? -EINVAL : 0;
|
|
|
|
reqsize += len_args(out->numargs, out->args);
|
|
|
|
if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
|
|
return -EINVAL;
|
|
else if (reqsize > nbytes) {
|
|
struct fuse_arg *lastarg = &out->args[out->numargs-1];
|
|
unsigned diffsize = reqsize - nbytes;
|
|
if (diffsize > lastarg->size)
|
|
return -EINVAL;
|
|
lastarg->size -= diffsize;
|
|
}
|
|
return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
|
|
out->page_zeroing);
|
|
}
|
|
|
|
/*
|
|
* Write a single reply to a request. First the header is copied from
|
|
* the write buffer. The request is then searched on the processing
|
|
* list by the unique ID found in the header. If found, then remove
|
|
* it from the list and copy the rest of the buffer to the request.
|
|
* The request is finished by calling request_end()
|
|
*/
|
|
static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
{
|
|
int err;
|
|
struct fuse_conn *fc = fud->fc;
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
struct fuse_req *req;
|
|
struct fuse_out_header oh;
|
|
|
|
err = -EINVAL;
|
|
if (nbytes < sizeof(struct fuse_out_header))
|
|
goto out;
|
|
|
|
err = fuse_copy_one(cs, &oh, sizeof(oh));
|
|
if (err)
|
|
goto copy_finish;
|
|
|
|
err = -EINVAL;
|
|
if (oh.len != nbytes)
|
|
goto copy_finish;
|
|
|
|
/*
|
|
* Zero oh.unique indicates unsolicited notification message
|
|
* and error contains notification code.
|
|
*/
|
|
if (!oh.unique) {
|
|
err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
|
|
goto out;
|
|
}
|
|
|
|
err = -EINVAL;
|
|
if (oh.error <= -1000 || oh.error > 0)
|
|
goto copy_finish;
|
|
|
|
spin_lock(&fpq->lock);
|
|
req = NULL;
|
|
if (fpq->connected)
|
|
req = request_find(fpq, oh.unique & ~FUSE_INT_REQ_BIT);
|
|
|
|
err = -ENOENT;
|
|
if (!req) {
|
|
spin_unlock(&fpq->lock);
|
|
goto copy_finish;
|
|
}
|
|
|
|
/* Is it an interrupt reply ID? */
|
|
if (oh.unique & FUSE_INT_REQ_BIT) {
|
|
__fuse_get_request(req);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
err = 0;
|
|
if (nbytes != sizeof(struct fuse_out_header))
|
|
err = -EINVAL;
|
|
else if (oh.error == -ENOSYS)
|
|
fc->no_interrupt = 1;
|
|
else if (oh.error == -EAGAIN)
|
|
err = queue_interrupt(&fc->iq, req);
|
|
|
|
fuse_put_request(fc, req);
|
|
|
|
goto copy_finish;
|
|
}
|
|
|
|
clear_bit(FR_SENT, &req->flags);
|
|
list_move(&req->list, &fpq->io);
|
|
req->out.h = oh;
|
|
set_bit(FR_LOCKED, &req->flags);
|
|
spin_unlock(&fpq->lock);
|
|
cs->req = req;
|
|
if (!req->out.page_replace)
|
|
cs->move_pages = 0;
|
|
|
|
err = copy_out_args(cs, &req->out, nbytes);
|
|
fuse_copy_finish(cs);
|
|
|
|
spin_lock(&fpq->lock);
|
|
clear_bit(FR_LOCKED, &req->flags);
|
|
if (!fpq->connected)
|
|
err = -ENOENT;
|
|
else if (err)
|
|
req->out.h.error = -EIO;
|
|
if (!test_bit(FR_PRIVATE, &req->flags))
|
|
list_del_init(&req->list);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
request_end(fc, req);
|
|
out:
|
|
return err ? err : nbytes;
|
|
|
|
copy_finish:
|
|
fuse_copy_finish(cs);
|
|
goto out;
|
|
}
|
|
|
|
static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
struct fuse_copy_state cs;
|
|
struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
if (!iter_is_iovec(from))
|
|
return -EINVAL;
|
|
|
|
fuse_copy_init(&cs, 0, from);
|
|
|
|
return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
|
|
}
|
|
|
|
static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
|
|
struct file *out, loff_t *ppos,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
unsigned nbuf;
|
|
unsigned idx;
|
|
struct pipe_buffer *bufs;
|
|
struct fuse_copy_state cs;
|
|
struct fuse_dev *fud;
|
|
size_t rem;
|
|
ssize_t ret;
|
|
|
|
fud = fuse_get_dev(out);
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
pipe_lock(pipe);
|
|
|
|
bufs = kvmalloc_array(pipe->nrbufs, sizeof(struct pipe_buffer),
|
|
GFP_KERNEL);
|
|
if (!bufs) {
|
|
pipe_unlock(pipe);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
nbuf = 0;
|
|
rem = 0;
|
|
for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
|
|
rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
|
|
|
|
ret = -EINVAL;
|
|
if (rem < len)
|
|
goto out_free;
|
|
|
|
rem = len;
|
|
while (rem) {
|
|
struct pipe_buffer *ibuf;
|
|
struct pipe_buffer *obuf;
|
|
|
|
BUG_ON(nbuf >= pipe->buffers);
|
|
BUG_ON(!pipe->nrbufs);
|
|
ibuf = &pipe->bufs[pipe->curbuf];
|
|
obuf = &bufs[nbuf];
|
|
|
|
if (rem >= ibuf->len) {
|
|
*obuf = *ibuf;
|
|
ibuf->ops = NULL;
|
|
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
|
|
pipe->nrbufs--;
|
|
} else {
|
|
if (!pipe_buf_get(pipe, ibuf))
|
|
goto out_free;
|
|
|
|
*obuf = *ibuf;
|
|
obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
|
|
obuf->len = rem;
|
|
ibuf->offset += obuf->len;
|
|
ibuf->len -= obuf->len;
|
|
}
|
|
nbuf++;
|
|
rem -= obuf->len;
|
|
}
|
|
pipe_unlock(pipe);
|
|
|
|
fuse_copy_init(&cs, 0, NULL);
|
|
cs.pipebufs = bufs;
|
|
cs.nr_segs = nbuf;
|
|
cs.pipe = pipe;
|
|
|
|
if (flags & SPLICE_F_MOVE)
|
|
cs.move_pages = 1;
|
|
|
|
ret = fuse_dev_do_write(fud, &cs, len);
|
|
|
|
pipe_lock(pipe);
|
|
out_free:
|
|
for (idx = 0; idx < nbuf; idx++)
|
|
pipe_buf_release(pipe, &bufs[idx]);
|
|
pipe_unlock(pipe);
|
|
|
|
kvfree(bufs);
|
|
return ret;
|
|
}
|
|
|
|
static __poll_t fuse_dev_poll(struct file *file, poll_table *wait)
|
|
{
|
|
__poll_t mask = EPOLLOUT | EPOLLWRNORM;
|
|
struct fuse_iqueue *fiq;
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (!fud)
|
|
return EPOLLERR;
|
|
|
|
fiq = &fud->fc->iq;
|
|
poll_wait(file, &fiq->waitq, wait);
|
|
|
|
spin_lock(&fiq->lock);
|
|
if (!fiq->connected)
|
|
mask = EPOLLERR;
|
|
else if (request_pending(fiq))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
spin_unlock(&fiq->lock);
|
|
|
|
return mask;
|
|
}
|
|
|
|
/* Abort all requests on the given list (pending or processing) */
|
|
static void end_requests(struct fuse_conn *fc, struct list_head *head)
|
|
{
|
|
while (!list_empty(head)) {
|
|
struct fuse_req *req;
|
|
req = list_entry(head->next, struct fuse_req, list);
|
|
req->out.h.error = -ECONNABORTED;
|
|
clear_bit(FR_SENT, &req->flags);
|
|
list_del_init(&req->list);
|
|
request_end(fc, req);
|
|
}
|
|
}
|
|
|
|
static void end_polls(struct fuse_conn *fc)
|
|
{
|
|
struct rb_node *p;
|
|
|
|
p = rb_first(&fc->polled_files);
|
|
|
|
while (p) {
|
|
struct fuse_file *ff;
|
|
ff = rb_entry(p, struct fuse_file, polled_node);
|
|
wake_up_interruptible_all(&ff->poll_wait);
|
|
|
|
p = rb_next(p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Abort all requests.
|
|
*
|
|
* Emergency exit in case of a malicious or accidental deadlock, or just a hung
|
|
* filesystem.
|
|
*
|
|
* The same effect is usually achievable through killing the filesystem daemon
|
|
* and all users of the filesystem. The exception is the combination of an
|
|
* asynchronous request and the tricky deadlock (see
|
|
* Documentation/filesystems/fuse.txt).
|
|
*
|
|
* Aborting requests under I/O goes as follows: 1: Separate out unlocked
|
|
* requests, they should be finished off immediately. Locked requests will be
|
|
* finished after unlock; see unlock_request(). 2: Finish off the unlocked
|
|
* requests. It is possible that some request will finish before we can. This
|
|
* is OK, the request will in that case be removed from the list before we touch
|
|
* it.
|
|
*/
|
|
void fuse_abort_conn(struct fuse_conn *fc)
|
|
{
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
|
|
spin_lock(&fc->lock);
|
|
if (fc->connected) {
|
|
struct fuse_dev *fud;
|
|
struct fuse_req *req, *next;
|
|
LIST_HEAD(to_end);
|
|
unsigned int i;
|
|
|
|
/* Background queuing checks fc->connected under bg_lock */
|
|
spin_lock(&fc->bg_lock);
|
|
fc->connected = 0;
|
|
spin_unlock(&fc->bg_lock);
|
|
|
|
fuse_set_initialized(fc);
|
|
list_for_each_entry(fud, &fc->devices, entry) {
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
|
|
spin_lock(&fpq->lock);
|
|
fpq->connected = 0;
|
|
list_for_each_entry_safe(req, next, &fpq->io, list) {
|
|
req->out.h.error = -ECONNABORTED;
|
|
spin_lock(&req->waitq.lock);
|
|
set_bit(FR_ABORTED, &req->flags);
|
|
if (!test_bit(FR_LOCKED, &req->flags)) {
|
|
set_bit(FR_PRIVATE, &req->flags);
|
|
__fuse_get_request(req);
|
|
list_move(&req->list, &to_end);
|
|
}
|
|
spin_unlock(&req->waitq.lock);
|
|
}
|
|
for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
|
list_splice_tail_init(&fpq->processing[i],
|
|
&to_end);
|
|
spin_unlock(&fpq->lock);
|
|
}
|
|
spin_lock(&fc->bg_lock);
|
|
fc->blocked = 0;
|
|
fc->max_background = UINT_MAX;
|
|
flush_bg_queue(fc);
|
|
spin_unlock(&fc->bg_lock);
|
|
|
|
spin_lock(&fiq->lock);
|
|
fiq->connected = 0;
|
|
list_for_each_entry(req, &fiq->pending, list)
|
|
clear_bit(FR_PENDING, &req->flags);
|
|
list_splice_tail_init(&fiq->pending, &to_end);
|
|
while (forget_pending(fiq))
|
|
kfree(dequeue_forget(fiq, 1, NULL));
|
|
wake_up_all(&fiq->waitq);
|
|
spin_unlock(&fiq->lock);
|
|
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
|
|
end_polls(fc);
|
|
wake_up_all(&fc->blocked_waitq);
|
|
spin_unlock(&fc->lock);
|
|
|
|
end_requests(fc, &to_end);
|
|
} else {
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_abort_conn);
|
|
|
|
void fuse_wait_aborted(struct fuse_conn *fc)
|
|
{
|
|
/* matches implicit memory barrier in fuse_drop_waiting() */
|
|
smp_mb();
|
|
wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
|
|
}
|
|
|
|
int fuse_dev_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (fud) {
|
|
struct fuse_conn *fc = fud->fc;
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
LIST_HEAD(to_end);
|
|
unsigned int i;
|
|
|
|
spin_lock(&fpq->lock);
|
|
WARN_ON(!list_empty(&fpq->io));
|
|
for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
|
list_splice_init(&fpq->processing[i], &to_end);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
end_requests(fc, &to_end);
|
|
|
|
/* Are we the last open device? */
|
|
if (atomic_dec_and_test(&fc->dev_count)) {
|
|
WARN_ON(fc->iq.fasync != NULL);
|
|
fuse_abort_conn(fc);
|
|
}
|
|
fuse_dev_free(fud);
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_dev_release);
|
|
|
|
static int fuse_dev_fasync(int fd, struct file *file, int on)
|
|
{
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
/* No locking - fasync_helper does its own locking */
|
|
return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
|
|
}
|
|
|
|
static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
|
|
{
|
|
struct fuse_dev *fud;
|
|
|
|
if (new->private_data)
|
|
return -EINVAL;
|
|
|
|
fud = fuse_dev_alloc(fc);
|
|
if (!fud)
|
|
return -ENOMEM;
|
|
|
|
new->private_data = fud;
|
|
atomic_inc(&fc->dev_count);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int err = -ENOTTY;
|
|
|
|
if (cmd == FUSE_DEV_IOC_CLONE) {
|
|
int oldfd;
|
|
|
|
err = -EFAULT;
|
|
if (!get_user(oldfd, (__u32 __user *) arg)) {
|
|
struct file *old = fget(oldfd);
|
|
|
|
err = -EINVAL;
|
|
if (old) {
|
|
struct fuse_dev *fud = NULL;
|
|
|
|
/*
|
|
* Check against file->f_op because CUSE
|
|
* uses the same ioctl handler.
|
|
*/
|
|
if (old->f_op == file->f_op &&
|
|
old->f_cred->user_ns == file->f_cred->user_ns)
|
|
fud = fuse_get_dev(old);
|
|
|
|
if (fud) {
|
|
mutex_lock(&fuse_mutex);
|
|
err = fuse_device_clone(fud->fc, file);
|
|
mutex_unlock(&fuse_mutex);
|
|
}
|
|
fput(old);
|
|
}
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
const struct file_operations fuse_dev_operations = {
|
|
.owner = THIS_MODULE,
|
|
.open = fuse_dev_open,
|
|
.llseek = no_llseek,
|
|
.read_iter = fuse_dev_read,
|
|
.splice_read = fuse_dev_splice_read,
|
|
.write_iter = fuse_dev_write,
|
|
.splice_write = fuse_dev_splice_write,
|
|
.poll = fuse_dev_poll,
|
|
.release = fuse_dev_release,
|
|
.fasync = fuse_dev_fasync,
|
|
.unlocked_ioctl = fuse_dev_ioctl,
|
|
.compat_ioctl = fuse_dev_ioctl,
|
|
};
|
|
EXPORT_SYMBOL_GPL(fuse_dev_operations);
|
|
|
|
static struct miscdevice fuse_miscdevice = {
|
|
.minor = FUSE_MINOR,
|
|
.name = "fuse",
|
|
.fops = &fuse_dev_operations,
|
|
};
|
|
|
|
int __init fuse_dev_init(void)
|
|
{
|
|
int err = -ENOMEM;
|
|
fuse_req_cachep = kmem_cache_create("fuse_request",
|
|
sizeof(struct fuse_req),
|
|
0, 0, NULL);
|
|
if (!fuse_req_cachep)
|
|
goto out;
|
|
|
|
err = misc_register(&fuse_miscdevice);
|
|
if (err)
|
|
goto out_cache_clean;
|
|
|
|
return 0;
|
|
|
|
out_cache_clean:
|
|
kmem_cache_destroy(fuse_req_cachep);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
void fuse_dev_cleanup(void)
|
|
{
|
|
misc_deregister(&fuse_miscdevice);
|
|
kmem_cache_destroy(fuse_req_cachep);
|
|
}
|