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![Geert Uytterhoeven](/assets/img/avatar_default.png)
fs/fuse/dev.c:1357: warning: ‘total_len’ may be used uninitialized in this function Initialize total_len to zero, else its value will be undefined. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
1890 lines
42 KiB
C
1890 lines
42 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/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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MODULE_ALIAS_MISCDEV(FUSE_MINOR);
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MODULE_ALIAS("devname:fuse");
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static struct kmem_cache *fuse_req_cachep;
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static struct fuse_conn *fuse_get_conn(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 file->private_data;
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}
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static void fuse_request_init(struct fuse_req *req)
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{
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memset(req, 0, sizeof(*req));
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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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atomic_set(&req->count, 1);
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}
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struct fuse_req *fuse_request_alloc(void)
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{
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struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
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if (req)
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fuse_request_init(req);
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return req;
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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(void)
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{
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struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_NOFS);
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if (req)
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fuse_request_init(req);
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return req;
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}
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void fuse_request_free(struct fuse_req *req)
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{
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kmem_cache_free(fuse_req_cachep, req);
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}
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static void block_sigs(sigset_t *oldset)
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{
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sigset_t mask;
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siginitsetinv(&mask, sigmask(SIGKILL));
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sigprocmask(SIG_BLOCK, &mask, oldset);
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}
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static void restore_sigs(sigset_t *oldset)
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{
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sigprocmask(SIG_SETMASK, oldset, NULL);
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}
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static void __fuse_get_request(struct fuse_req *req)
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{
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atomic_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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BUG_ON(atomic_read(&req->count) < 2);
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atomic_dec(&req->count);
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}
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static void fuse_req_init_context(struct fuse_req *req)
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{
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req->in.h.uid = current_fsuid();
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req->in.h.gid = current_fsgid();
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req->in.h.pid = current->pid;
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}
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struct fuse_req *fuse_get_req(struct fuse_conn *fc)
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{
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struct fuse_req *req;
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sigset_t oldset;
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int intr;
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int err;
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atomic_inc(&fc->num_waiting);
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block_sigs(&oldset);
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intr = wait_event_interruptible(fc->blocked_waitq, !fc->blocked);
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restore_sigs(&oldset);
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err = -EINTR;
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if (intr)
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goto out;
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err = -ENOTCONN;
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if (!fc->connected)
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goto out;
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req = fuse_request_alloc();
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err = -ENOMEM;
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if (!req)
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goto out;
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fuse_req_init_context(req);
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req->waiting = 1;
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return req;
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out:
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atomic_dec(&fc->num_waiting);
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return ERR_PTR(err);
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}
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EXPORT_SYMBOL_GPL(fuse_get_req);
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/*
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* Return request in fuse_file->reserved_req. However that may
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* currently be in use. If that is the case, wait for it to become
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* available.
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*/
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static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
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struct file *file)
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{
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struct fuse_req *req = NULL;
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struct fuse_file *ff = file->private_data;
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do {
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wait_event(fc->reserved_req_waitq, ff->reserved_req);
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spin_lock(&fc->lock);
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if (ff->reserved_req) {
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req = ff->reserved_req;
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ff->reserved_req = NULL;
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get_file(file);
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req->stolen_file = file;
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}
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spin_unlock(&fc->lock);
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} while (!req);
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return req;
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}
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/*
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* Put stolen request back into fuse_file->reserved_req
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*/
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static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
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{
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struct file *file = req->stolen_file;
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struct fuse_file *ff = file->private_data;
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spin_lock(&fc->lock);
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fuse_request_init(req);
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BUG_ON(ff->reserved_req);
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ff->reserved_req = req;
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wake_up_all(&fc->reserved_req_waitq);
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spin_unlock(&fc->lock);
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fput(file);
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}
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/*
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* Gets a requests for a file operation, always succeeds
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*
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* This is used for sending the FLUSH request, which must get to
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* userspace, due to POSIX locks which may need to be unlocked.
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*
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* If allocation fails due to OOM, use the reserved request in
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* fuse_file.
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*
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* This is very unlikely to deadlock accidentally, since the
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* filesystem should not have it's own file open. If deadlock is
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* intentional, it can still be broken by "aborting" the filesystem.
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*/
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struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
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{
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struct fuse_req *req;
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atomic_inc(&fc->num_waiting);
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wait_event(fc->blocked_waitq, !fc->blocked);
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req = fuse_request_alloc();
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if (!req)
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req = get_reserved_req(fc, file);
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fuse_req_init_context(req);
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req->waiting = 1;
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return req;
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}
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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 (atomic_dec_and_test(&req->count)) {
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if (req->waiting)
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atomic_dec(&fc->num_waiting);
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if (req->stolen_file)
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put_reserved_req(fc, req);
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else
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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_conn *fc)
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{
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fc->reqctr++;
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/* zero is special */
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if (fc->reqctr == 0)
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fc->reqctr = 1;
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return fc->reqctr;
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}
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static void queue_request(struct fuse_conn *fc, 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, &fc->pending);
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req->state = FUSE_REQ_PENDING;
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if (!req->waiting) {
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req->waiting = 1;
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atomic_inc(&fc->num_waiting);
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}
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wake_up(&fc->waitq);
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kill_fasync(&fc->fasync, SIGIO, POLL_IN);
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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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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_entry(fc->bg_queue.next, struct fuse_req, list);
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list_del(&req->list);
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fc->active_background++;
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req->in.h.unique = fuse_get_unique(fc);
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queue_request(fc, req);
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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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* Called with fc->lock, unlocks it
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*/
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static void request_end(struct fuse_conn *fc, struct fuse_req *req)
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__releases(fc->lock)
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{
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void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
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req->end = NULL;
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list_del(&req->list);
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list_del(&req->intr_entry);
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req->state = FUSE_REQ_FINISHED;
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if (req->background) {
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if (fc->num_background == fc->max_background) {
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fc->blocked = 0;
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wake_up_all(&fc->blocked_waitq);
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}
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if (fc->num_background == fc->congestion_threshold &&
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fc->connected && fc->bdi_initialized) {
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clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
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clear_bdi_congested(&fc->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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}
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spin_unlock(&fc->lock);
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wake_up(&req->waitq);
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if (end)
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end(fc, req);
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fuse_put_request(fc, req);
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}
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static void wait_answer_interruptible(struct fuse_conn *fc,
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struct fuse_req *req)
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__releases(fc->lock)
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__acquires(fc->lock)
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{
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if (signal_pending(current))
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return;
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spin_unlock(&fc->lock);
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wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
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spin_lock(&fc->lock);
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}
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static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
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{
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list_add_tail(&req->intr_entry, &fc->interrupts);
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wake_up(&fc->waitq);
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kill_fasync(&fc->fasync, SIGIO, POLL_IN);
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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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__releases(fc->lock)
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__acquires(fc->lock)
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{
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if (!fc->no_interrupt) {
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/* Any signal may interrupt this */
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wait_answer_interruptible(fc, req);
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if (req->aborted)
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goto aborted;
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if (req->state == FUSE_REQ_FINISHED)
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return;
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req->interrupted = 1;
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if (req->state == FUSE_REQ_SENT)
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queue_interrupt(fc, req);
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}
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if (!req->force) {
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sigset_t oldset;
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/* Only fatal signals may interrupt this */
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block_sigs(&oldset);
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wait_answer_interruptible(fc, req);
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restore_sigs(&oldset);
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if (req->aborted)
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goto aborted;
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if (req->state == FUSE_REQ_FINISHED)
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return;
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/* Request is not yet in userspace, bail out */
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if (req->state == FUSE_REQ_PENDING) {
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list_del(&req->list);
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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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}
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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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spin_unlock(&fc->lock);
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wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
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spin_lock(&fc->lock);
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if (!req->aborted)
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return;
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aborted:
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BUG_ON(req->state != FUSE_REQ_FINISHED);
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if (req->locked) {
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/* This is uninterruptible sleep, because data is
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being copied to/from the buffers of req. During
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locked state, there mustn't be any filesystem
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operation (e.g. page fault), since that could lead
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to deadlock */
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spin_unlock(&fc->lock);
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wait_event(req->waitq, !req->locked);
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spin_lock(&fc->lock);
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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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req->isreply = 1;
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spin_lock(&fc->lock);
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if (!fc->connected)
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req->out.h.error = -ENOTCONN;
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else if (fc->conn_error)
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req->out.h.error = -ECONNREFUSED;
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else {
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req->in.h.unique = fuse_get_unique(fc);
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queue_request(fc, 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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request_wait_answer(fc, req);
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}
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spin_unlock(&fc->lock);
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}
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EXPORT_SYMBOL_GPL(fuse_request_send);
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static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
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struct fuse_req *req)
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{
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req->background = 1;
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fc->num_background++;
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if (fc->num_background == fc->max_background)
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fc->blocked = 1;
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if (fc->num_background == fc->congestion_threshold &&
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fc->bdi_initialized) {
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set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
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set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
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}
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list_add_tail(&req->list, &fc->bg_queue);
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flush_bg_queue(fc);
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}
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static void fuse_request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
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{
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spin_lock(&fc->lock);
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if (fc->connected) {
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fuse_request_send_nowait_locked(fc, req);
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spin_unlock(&fc->lock);
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} else {
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req->out.h.error = -ENOTCONN;
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request_end(fc, req);
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}
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}
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void fuse_request_send_noreply(struct fuse_conn *fc, struct fuse_req *req)
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{
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req->isreply = 0;
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fuse_request_send_nowait(fc, req);
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}
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void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
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{
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req->isreply = 1;
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fuse_request_send_nowait(fc, req);
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}
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EXPORT_SYMBOL_GPL(fuse_request_send_background);
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static int fuse_request_send_notify_reply(struct fuse_conn *fc,
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struct fuse_req *req, u64 unique)
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{
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int err = -ENODEV;
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req->isreply = 0;
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req->in.h.unique = unique;
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spin_lock(&fc->lock);
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if (fc->connected) {
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queue_request(fc, req);
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err = 0;
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}
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spin_unlock(&fc->lock);
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return err;
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}
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|
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/*
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* Called under fc->lock
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*
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* fc->connected must have been checked previously
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*/
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void fuse_request_send_background_locked(struct fuse_conn *fc,
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struct fuse_req *req)
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{
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req->isreply = 1;
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fuse_request_send_nowait_locked(fc, req);
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}
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|
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/*
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* Lock the request. Up to the next unlock_request() there mustn't be
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* anything that could cause a page-fault. If the request was already
|
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* aborted bail out.
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*/
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static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
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{
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int err = 0;
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if (req) {
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spin_lock(&fc->lock);
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if (req->aborted)
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err = -ENOENT;
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else
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req->locked = 1;
|
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spin_unlock(&fc->lock);
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}
|
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return err;
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}
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|
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/*
|
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* Unlock request. If it was aborted during being locked, the
|
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* requester thread is currently waiting for it to be unlocked, so
|
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* wake it up.
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*/
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static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
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{
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if (req) {
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spin_lock(&fc->lock);
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req->locked = 0;
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if (req->aborted)
|
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wake_up(&req->waitq);
|
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spin_unlock(&fc->lock);
|
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}
|
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}
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|
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struct fuse_copy_state {
|
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struct fuse_conn *fc;
|
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int write;
|
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struct fuse_req *req;
|
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const struct iovec *iov;
|
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struct pipe_buffer *pipebufs;
|
|
struct pipe_buffer *currbuf;
|
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struct pipe_inode_info *pipe;
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unsigned long nr_segs;
|
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unsigned long seglen;
|
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unsigned long addr;
|
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struct page *pg;
|
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void *mapaddr;
|
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void *buf;
|
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unsigned len;
|
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unsigned move_pages:1;
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|
};
|
|
|
|
static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
|
|
int write,
|
|
const struct iovec *iov, unsigned long nr_segs)
|
|
{
|
|
memset(cs, 0, sizeof(*cs));
|
|
cs->fc = fc;
|
|
cs->write = write;
|
|
cs->iov = iov;
|
|
cs->nr_segs = nr_segs;
|
|
}
|
|
|
|
/* 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->ops->unmap(cs->pipe, buf, cs->mapaddr);
|
|
} else {
|
|
kunmap(buf->page);
|
|
buf->len = PAGE_SIZE - cs->len;
|
|
}
|
|
cs->currbuf = NULL;
|
|
cs->mapaddr = NULL;
|
|
} else if (cs->mapaddr) {
|
|
kunmap(cs->pg);
|
|
if (cs->write) {
|
|
flush_dcache_page(cs->pg);
|
|
set_page_dirty_lock(cs->pg);
|
|
}
|
|
put_page(cs->pg);
|
|
cs->mapaddr = 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)
|
|
{
|
|
unsigned long offset;
|
|
int err;
|
|
|
|
unlock_request(cs->fc, cs->req);
|
|
fuse_copy_finish(cs);
|
|
if (cs->pipebufs) {
|
|
struct pipe_buffer *buf = cs->pipebufs;
|
|
|
|
if (!cs->write) {
|
|
err = buf->ops->confirm(cs->pipe, buf);
|
|
if (err)
|
|
return err;
|
|
|
|
BUG_ON(!cs->nr_segs);
|
|
cs->currbuf = buf;
|
|
cs->mapaddr = buf->ops->map(cs->pipe, buf, 0);
|
|
cs->len = buf->len;
|
|
cs->buf = cs->mapaddr + buf->offset;
|
|
cs->pipebufs++;
|
|
cs->nr_segs--;
|
|
} else {
|
|
struct page *page;
|
|
|
|
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->mapaddr = kmap(page);
|
|
cs->buf = cs->mapaddr;
|
|
cs->len = PAGE_SIZE;
|
|
cs->pipebufs++;
|
|
cs->nr_segs++;
|
|
}
|
|
} else {
|
|
if (!cs->seglen) {
|
|
BUG_ON(!cs->nr_segs);
|
|
cs->seglen = cs->iov[0].iov_len;
|
|
cs->addr = (unsigned long) cs->iov[0].iov_base;
|
|
cs->iov++;
|
|
cs->nr_segs--;
|
|
}
|
|
err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
|
|
if (err < 0)
|
|
return err;
|
|
BUG_ON(err != 1);
|
|
offset = cs->addr % PAGE_SIZE;
|
|
cs->mapaddr = kmap(cs->pg);
|
|
cs->buf = cs->mapaddr + offset;
|
|
cs->len = min(PAGE_SIZE - offset, cs->seglen);
|
|
cs->seglen -= cs->len;
|
|
cs->addr += cs->len;
|
|
}
|
|
|
|
return lock_request(cs->fc, 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) {
|
|
if (cs->write)
|
|
memcpy(cs->buf, *val, ncpy);
|
|
else
|
|
memcpy(*val, cs->buf, ncpy);
|
|
*val += ncpy;
|
|
}
|
|
*size -= ncpy;
|
|
cs->len -= ncpy;
|
|
cs->buf += 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))) {
|
|
printk(KERN_WARNING "fuse: trying to steal weird page\n");
|
|
printk(KERN_WARNING " 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;
|
|
struct address_space *mapping;
|
|
pgoff_t index;
|
|
|
|
unlock_request(cs->fc, cs->req);
|
|
fuse_copy_finish(cs);
|
|
|
|
err = buf->ops->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 (buf->ops->steal(cs->pipe, buf) != 0)
|
|
goto out_fallback;
|
|
|
|
newpage = buf->page;
|
|
|
|
if (WARN_ON(!PageUptodate(newpage)))
|
|
return -EIO;
|
|
|
|
ClearPageMappedToDisk(newpage);
|
|
|
|
if (fuse_check_page(newpage) != 0)
|
|
goto out_fallback_unlock;
|
|
|
|
mapping = oldpage->mapping;
|
|
index = oldpage->index;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
remove_from_page_cache(oldpage);
|
|
page_cache_release(oldpage);
|
|
|
|
err = add_to_page_cache_locked(newpage, mapping, index, GFP_KERNEL);
|
|
if (err) {
|
|
printk(KERN_WARNING "fuse_try_move_page: failed to add page");
|
|
goto out_fallback_unlock;
|
|
}
|
|
page_cache_get(newpage);
|
|
|
|
if (!(buf->flags & PIPE_BUF_FLAG_LRU))
|
|
lru_cache_add_file(newpage);
|
|
|
|
err = 0;
|
|
spin_lock(&cs->fc->lock);
|
|
if (cs->req->aborted)
|
|
err = -ENOENT;
|
|
else
|
|
*pagep = newpage;
|
|
spin_unlock(&cs->fc->lock);
|
|
|
|
if (err) {
|
|
unlock_page(newpage);
|
|
page_cache_release(newpage);
|
|
return err;
|
|
}
|
|
|
|
unlock_page(oldpage);
|
|
page_cache_release(oldpage);
|
|
cs->len = 0;
|
|
|
|
return 0;
|
|
|
|
out_fallback_unlock:
|
|
unlock_page(newpage);
|
|
out_fallback:
|
|
cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
|
|
cs->buf = cs->mapaddr + buf->offset;
|
|
|
|
err = lock_request(cs->fc, 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;
|
|
|
|
if (cs->nr_segs == cs->pipe->buffers)
|
|
return -EIO;
|
|
|
|
unlock_request(cs->fc, cs->req);
|
|
fuse_copy_finish(cs);
|
|
|
|
buf = cs->pipebufs;
|
|
page_cache_get(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) {
|
|
void *mapaddr = kmap_atomic(page, KM_USER1);
|
|
memset(mapaddr, 0, PAGE_SIZE);
|
|
kunmap_atomic(mapaddr, KM_USER1);
|
|
}
|
|
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, KM_USER1);
|
|
void *buf = mapaddr + offset;
|
|
offset += fuse_copy_do(cs, &buf, &count);
|
|
kunmap_atomic(mapaddr, KM_USER1);
|
|
} 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;
|
|
unsigned offset = req->page_offset;
|
|
unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset);
|
|
|
|
for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
|
|
int err;
|
|
|
|
err = fuse_copy_page(cs, &req->pages[i], offset, count,
|
|
zeroing);
|
|
if (err)
|
|
return err;
|
|
|
|
nbytes -= count;
|
|
count = min(nbytes, (unsigned) PAGE_SIZE);
|
|
offset = 0;
|
|
}
|
|
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 request_pending(struct fuse_conn *fc)
|
|
{
|
|
return !list_empty(&fc->pending) || !list_empty(&fc->interrupts);
|
|
}
|
|
|
|
/* Wait until a request is available on the pending list */
|
|
static void request_wait(struct fuse_conn *fc)
|
|
__releases(fc->lock)
|
|
__acquires(fc->lock)
|
|
{
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
|
|
add_wait_queue_exclusive(&fc->waitq, &wait);
|
|
while (fc->connected && !request_pending(fc)) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
if (signal_pending(current))
|
|
break;
|
|
|
|
spin_unlock(&fc->lock);
|
|
schedule();
|
|
spin_lock(&fc->lock);
|
|
}
|
|
set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(&fc->waitq, &wait);
|
|
}
|
|
|
|
/*
|
|
* 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 fc->lock held, releases it
|
|
*/
|
|
static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
|
|
size_t nbytes, struct fuse_req *req)
|
|
__releases(fc->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);
|
|
req->intr_unique = fuse_get_unique(fc);
|
|
memset(&ih, 0, sizeof(ih));
|
|
memset(&arg, 0, sizeof(arg));
|
|
ih.len = reqsize;
|
|
ih.opcode = FUSE_INTERRUPT;
|
|
ih.unique = req->intr_unique;
|
|
arg.unique = req->in.h.unique;
|
|
|
|
spin_unlock(&fc->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;
|
|
}
|
|
|
|
/*
|
|
* 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_conn *fc, struct file *file,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
{
|
|
int err;
|
|
struct fuse_req *req;
|
|
struct fuse_in *in;
|
|
unsigned reqsize;
|
|
|
|
restart:
|
|
spin_lock(&fc->lock);
|
|
err = -EAGAIN;
|
|
if ((file->f_flags & O_NONBLOCK) && fc->connected &&
|
|
!request_pending(fc))
|
|
goto err_unlock;
|
|
|
|
request_wait(fc);
|
|
err = -ENODEV;
|
|
if (!fc->connected)
|
|
goto err_unlock;
|
|
err = -ERESTARTSYS;
|
|
if (!request_pending(fc))
|
|
goto err_unlock;
|
|
|
|
if (!list_empty(&fc->interrupts)) {
|
|
req = list_entry(fc->interrupts.next, struct fuse_req,
|
|
intr_entry);
|
|
return fuse_read_interrupt(fc, cs, nbytes, req);
|
|
}
|
|
|
|
req = list_entry(fc->pending.next, struct fuse_req, list);
|
|
req->state = FUSE_REQ_READING;
|
|
list_move(&req->list, &fc->io);
|
|
|
|
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_unlock(&fc->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(&fc->lock);
|
|
req->locked = 0;
|
|
if (req->aborted) {
|
|
request_end(fc, req);
|
|
return -ENODEV;
|
|
}
|
|
if (err) {
|
|
req->out.h.error = -EIO;
|
|
request_end(fc, req);
|
|
return err;
|
|
}
|
|
if (!req->isreply)
|
|
request_end(fc, req);
|
|
else {
|
|
req->state = FUSE_REQ_SENT;
|
|
list_move_tail(&req->list, &fc->processing);
|
|
if (req->interrupted)
|
|
queue_interrupt(fc, req);
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
return reqsize;
|
|
|
|
err_unlock:
|
|
spin_unlock(&fc->lock);
|
|
return err;
|
|
}
|
|
|
|
static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
|
|
unsigned long nr_segs, loff_t pos)
|
|
{
|
|
struct fuse_copy_state cs;
|
|
struct file *file = iocb->ki_filp;
|
|
struct fuse_conn *fc = fuse_get_conn(file);
|
|
if (!fc)
|
|
return -EPERM;
|
|
|
|
fuse_copy_init(&cs, fc, 1, iov, nr_segs);
|
|
|
|
return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
|
|
}
|
|
|
|
static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe,
|
|
struct pipe_buffer *buf)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static const struct pipe_buf_operations fuse_dev_pipe_buf_ops = {
|
|
.can_merge = 0,
|
|
.map = generic_pipe_buf_map,
|
|
.unmap = generic_pipe_buf_unmap,
|
|
.confirm = generic_pipe_buf_confirm,
|
|
.release = generic_pipe_buf_release,
|
|
.steal = fuse_dev_pipe_buf_steal,
|
|
.get = generic_pipe_buf_get,
|
|
};
|
|
|
|
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 ret;
|
|
int page_nr = 0;
|
|
int do_wakeup = 0;
|
|
struct pipe_buffer *bufs;
|
|
struct fuse_copy_state cs;
|
|
struct fuse_conn *fc = fuse_get_conn(in);
|
|
if (!fc)
|
|
return -EPERM;
|
|
|
|
bufs = kmalloc(pipe->buffers * sizeof (struct pipe_buffer), GFP_KERNEL);
|
|
if (!bufs)
|
|
return -ENOMEM;
|
|
|
|
fuse_copy_init(&cs, fc, 1, NULL, 0);
|
|
cs.pipebufs = bufs;
|
|
cs.pipe = pipe;
|
|
ret = fuse_dev_do_read(fc, in, &cs, len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = 0;
|
|
pipe_lock(pipe);
|
|
|
|
if (!pipe->readers) {
|
|
send_sig(SIGPIPE, current, 0);
|
|
if (!ret)
|
|
ret = -EPIPE;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
|
|
ret = -EIO;
|
|
goto out_unlock;
|
|
}
|
|
|
|
while (page_nr < cs.nr_segs) {
|
|
int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
|
|
struct pipe_buffer *buf = pipe->bufs + newbuf;
|
|
|
|
buf->page = bufs[page_nr].page;
|
|
buf->offset = bufs[page_nr].offset;
|
|
buf->len = bufs[page_nr].len;
|
|
buf->ops = &fuse_dev_pipe_buf_ops;
|
|
|
|
pipe->nrbufs++;
|
|
page_nr++;
|
|
ret += buf->len;
|
|
|
|
if (pipe->inode)
|
|
do_wakeup = 1;
|
|
}
|
|
|
|
out_unlock:
|
|
pipe_unlock(pipe);
|
|
|
|
if (do_wakeup) {
|
|
smp_mb();
|
|
if (waitqueue_active(&pipe->wait))
|
|
wake_up_interruptible(&pipe->wait);
|
|
kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
|
|
}
|
|
|
|
out:
|
|
for (; page_nr < cs.nr_segs; page_nr++)
|
|
page_cache_release(bufs[page_nr].page);
|
|
|
|
kfree(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;
|
|
|
|
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;
|
|
name.hash = full_name_hash(name.name, name.len);
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb)
|
|
err = fuse_reverse_inval_entry(fc->sb, outarg.parent, &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_CACHE_SHIFT;
|
|
offset = outarg.offset & ~PAGE_CACHE_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_CACHE_SIZE - offset);
|
|
err = fuse_copy_page(cs, &page, offset, this_num, 0);
|
|
if (!err && offset == 0 && (num != 0 || file_size == end))
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
page_cache_release(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)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < req->num_pages; i++) {
|
|
struct page *page = req->pages[i];
|
|
page_cache_release(page);
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
req = fuse_get_req(fc);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
offset = outarg->offset & ~PAGE_CACHE_MASK;
|
|
|
|
req->in.h.opcode = FUSE_NOTIFY_REPLY;
|
|
req->in.h.nodeid = outarg->nodeid;
|
|
req->in.numargs = 2;
|
|
req->in.argpages = 1;
|
|
req->page_offset = offset;
|
|
req->end = fuse_retrieve_end;
|
|
|
|
index = outarg->offset >> PAGE_CACHE_SHIFT;
|
|
file_size = i_size_read(inode);
|
|
num = outarg->size;
|
|
if (outarg->offset > file_size)
|
|
num = 0;
|
|
else if (outarg->offset + num > file_size)
|
|
num = file_size - outarg->offset;
|
|
|
|
while (num) {
|
|
struct page *page;
|
|
unsigned int this_num;
|
|
|
|
page = find_get_page(mapping, index);
|
|
if (!page)
|
|
break;
|
|
|
|
this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
|
|
req->pages[req->num_pages] = page;
|
|
req->num_pages++;
|
|
|
|
num -= this_num;
|
|
total_len += this_num;
|
|
}
|
|
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);
|
|
|
|
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)
|
|
{
|
|
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);
|
|
|
|
default:
|
|
fuse_copy_finish(cs);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Look up request on processing list by unique ID */
|
|
static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
|
|
{
|
|
struct list_head *entry;
|
|
|
|
list_for_each(entry, &fc->processing) {
|
|
struct fuse_req *req;
|
|
req = list_entry(entry, struct fuse_req, list);
|
|
if (req->in.h.unique == unique || req->intr_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_conn *fc,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
{
|
|
int err;
|
|
struct fuse_req *req;
|
|
struct fuse_out_header oh;
|
|
|
|
if (nbytes < sizeof(struct fuse_out_header))
|
|
return -EINVAL;
|
|
|
|
err = fuse_copy_one(cs, &oh, sizeof(oh));
|
|
if (err)
|
|
goto err_finish;
|
|
|
|
err = -EINVAL;
|
|
if (oh.len != nbytes)
|
|
goto err_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);
|
|
return err ? err : nbytes;
|
|
}
|
|
|
|
err = -EINVAL;
|
|
if (oh.error <= -1000 || oh.error > 0)
|
|
goto err_finish;
|
|
|
|
spin_lock(&fc->lock);
|
|
err = -ENOENT;
|
|
if (!fc->connected)
|
|
goto err_unlock;
|
|
|
|
req = request_find(fc, oh.unique);
|
|
if (!req)
|
|
goto err_unlock;
|
|
|
|
if (req->aborted) {
|
|
spin_unlock(&fc->lock);
|
|
fuse_copy_finish(cs);
|
|
spin_lock(&fc->lock);
|
|
request_end(fc, req);
|
|
return -ENOENT;
|
|
}
|
|
/* Is it an interrupt reply? */
|
|
if (req->intr_unique == oh.unique) {
|
|
err = -EINVAL;
|
|
if (nbytes != sizeof(struct fuse_out_header))
|
|
goto err_unlock;
|
|
|
|
if (oh.error == -ENOSYS)
|
|
fc->no_interrupt = 1;
|
|
else if (oh.error == -EAGAIN)
|
|
queue_interrupt(fc, req);
|
|
|
|
spin_unlock(&fc->lock);
|
|
fuse_copy_finish(cs);
|
|
return nbytes;
|
|
}
|
|
|
|
req->state = FUSE_REQ_WRITING;
|
|
list_move(&req->list, &fc->io);
|
|
req->out.h = oh;
|
|
req->locked = 1;
|
|
cs->req = req;
|
|
if (!req->out.page_replace)
|
|
cs->move_pages = 0;
|
|
spin_unlock(&fc->lock);
|
|
|
|
err = copy_out_args(cs, &req->out, nbytes);
|
|
fuse_copy_finish(cs);
|
|
|
|
spin_lock(&fc->lock);
|
|
req->locked = 0;
|
|
if (!err) {
|
|
if (req->aborted)
|
|
err = -ENOENT;
|
|
} else if (!req->aborted)
|
|
req->out.h.error = -EIO;
|
|
request_end(fc, req);
|
|
|
|
return err ? err : nbytes;
|
|
|
|
err_unlock:
|
|
spin_unlock(&fc->lock);
|
|
err_finish:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
|
|
unsigned long nr_segs, loff_t pos)
|
|
{
|
|
struct fuse_copy_state cs;
|
|
struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
|
|
if (!fc)
|
|
return -EPERM;
|
|
|
|
fuse_copy_init(&cs, fc, 0, iov, nr_segs);
|
|
|
|
return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
|
|
}
|
|
|
|
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_conn *fc;
|
|
size_t rem;
|
|
ssize_t ret;
|
|
|
|
fc = fuse_get_conn(out);
|
|
if (!fc)
|
|
return -EPERM;
|
|
|
|
bufs = kmalloc(pipe->buffers * sizeof (struct pipe_buffer), GFP_KERNEL);
|
|
if (!bufs)
|
|
return -ENOMEM;
|
|
|
|
pipe_lock(pipe);
|
|
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) {
|
|
pipe_unlock(pipe);
|
|
goto out;
|
|
}
|
|
|
|
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 {
|
|
ibuf->ops->get(pipe, ibuf);
|
|
*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, fc, 0, NULL, nbuf);
|
|
cs.pipebufs = bufs;
|
|
cs.pipe = pipe;
|
|
|
|
if (flags & SPLICE_F_MOVE)
|
|
cs.move_pages = 1;
|
|
|
|
ret = fuse_dev_do_write(fc, &cs, len);
|
|
|
|
for (idx = 0; idx < nbuf; idx++) {
|
|
struct pipe_buffer *buf = &bufs[idx];
|
|
buf->ops->release(pipe, buf);
|
|
}
|
|
out:
|
|
kfree(bufs);
|
|
return ret;
|
|
}
|
|
|
|
static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
|
|
{
|
|
unsigned mask = POLLOUT | POLLWRNORM;
|
|
struct fuse_conn *fc = fuse_get_conn(file);
|
|
if (!fc)
|
|
return POLLERR;
|
|
|
|
poll_wait(file, &fc->waitq, wait);
|
|
|
|
spin_lock(&fc->lock);
|
|
if (!fc->connected)
|
|
mask = POLLERR;
|
|
else if (request_pending(fc))
|
|
mask |= POLLIN | POLLRDNORM;
|
|
spin_unlock(&fc->lock);
|
|
|
|
return mask;
|
|
}
|
|
|
|
/*
|
|
* Abort all requests on the given list (pending or processing)
|
|
*
|
|
* This function releases and reacquires fc->lock
|
|
*/
|
|
static void end_requests(struct fuse_conn *fc, struct list_head *head)
|
|
__releases(fc->lock)
|
|
__acquires(fc->lock)
|
|
{
|
|
while (!list_empty(head)) {
|
|
struct fuse_req *req;
|
|
req = list_entry(head->next, struct fuse_req, list);
|
|
req->out.h.error = -ECONNABORTED;
|
|
request_end(fc, req);
|
|
spin_lock(&fc->lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Abort requests under I/O
|
|
*
|
|
* The requests are set to aborted and finished, and the request
|
|
* waiter is woken up. This will make request_wait_answer() wait
|
|
* until the request is unlocked and then return.
|
|
*
|
|
* If the request is asynchronous, then the end function needs to be
|
|
* called after waiting for the request to be unlocked (if it was
|
|
* locked).
|
|
*/
|
|
static void end_io_requests(struct fuse_conn *fc)
|
|
__releases(fc->lock)
|
|
__acquires(fc->lock)
|
|
{
|
|
while (!list_empty(&fc->io)) {
|
|
struct fuse_req *req =
|
|
list_entry(fc->io.next, struct fuse_req, list);
|
|
void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
|
|
|
|
req->aborted = 1;
|
|
req->out.h.error = -ECONNABORTED;
|
|
req->state = FUSE_REQ_FINISHED;
|
|
list_del_init(&req->list);
|
|
wake_up(&req->waitq);
|
|
if (end) {
|
|
req->end = NULL;
|
|
__fuse_get_request(req);
|
|
spin_unlock(&fc->lock);
|
|
wait_event(req->waitq, !req->locked);
|
|
end(fc, req);
|
|
fuse_put_request(fc, req);
|
|
spin_lock(&fc->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void end_queued_requests(struct fuse_conn *fc)
|
|
__releases(fc->lock)
|
|
__acquires(fc->lock)
|
|
{
|
|
fc->max_background = UINT_MAX;
|
|
flush_bg_queue(fc);
|
|
end_requests(fc, &fc->pending);
|
|
end_requests(fc, &fc->processing);
|
|
}
|
|
|
|
/*
|
|
* 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).
|
|
*
|
|
* During the aborting, progression of requests from the pending and
|
|
* processing lists onto the io list, and progression of new requests
|
|
* onto the pending list is prevented by req->connected being false.
|
|
*
|
|
* Progression of requests under I/O to the processing list is
|
|
* prevented by the req->aborted flag being true for these requests.
|
|
* For this reason requests on the io list must be aborted first.
|
|
*/
|
|
void fuse_abort_conn(struct fuse_conn *fc)
|
|
{
|
|
spin_lock(&fc->lock);
|
|
if (fc->connected) {
|
|
fc->connected = 0;
|
|
fc->blocked = 0;
|
|
end_io_requests(fc);
|
|
end_queued_requests(fc);
|
|
wake_up_all(&fc->waitq);
|
|
wake_up_all(&fc->blocked_waitq);
|
|
kill_fasync(&fc->fasync, SIGIO, POLL_IN);
|
|
}
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_abort_conn);
|
|
|
|
int fuse_dev_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct fuse_conn *fc = fuse_get_conn(file);
|
|
if (fc) {
|
|
spin_lock(&fc->lock);
|
|
fc->connected = 0;
|
|
fc->blocked = 0;
|
|
end_queued_requests(fc);
|
|
wake_up_all(&fc->blocked_waitq);
|
|
spin_unlock(&fc->lock);
|
|
fuse_conn_put(fc);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_dev_release);
|
|
|
|
static int fuse_dev_fasync(int fd, struct file *file, int on)
|
|
{
|
|
struct fuse_conn *fc = fuse_get_conn(file);
|
|
if (!fc)
|
|
return -EPERM;
|
|
|
|
/* No locking - fasync_helper does its own locking */
|
|
return fasync_helper(fd, file, on, &fc->fasync);
|
|
}
|
|
|
|
const struct file_operations fuse_dev_operations = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.read = do_sync_read,
|
|
.aio_read = fuse_dev_read,
|
|
.splice_read = fuse_dev_splice_read,
|
|
.write = do_sync_write,
|
|
.aio_write = fuse_dev_write,
|
|
.splice_write = fuse_dev_splice_write,
|
|
.poll = fuse_dev_poll,
|
|
.release = fuse_dev_release,
|
|
.fasync = fuse_dev_fasync,
|
|
};
|
|
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);
|
|
}
|