1/*
   2  FUSE: Filesystem in Userspace
   3  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
   4
   5  This program can be distributed under the terms of the GNU GPL.
   6  See the file COPYING.
   7*/
   8
   9#include "fuse_i.h"
  10
  11#include <linux/init.h>
  12#include <linux/module.h>
  13#include <linux/poll.h>
 
  14#include <linux/uio.h>
  15#include <linux/miscdevice.h>
  16#include <linux/pagemap.h>
  17#include <linux/file.h>
  18#include <linux/slab.h>
  19#include <linux/pipe_fs_i.h>
  20#include <linux/swap.h>
  21#include <linux/splice.h>
 
 
 
 
  22
  23MODULE_ALIAS_MISCDEV(FUSE_MINOR);
  24MODULE_ALIAS("devname:fuse");
  25
 
 
 
 
  26static struct kmem_cache *fuse_req_cachep;
  27
 
 
  28static struct fuse_dev *fuse_get_dev(struct file *file)
  29{
  30	/*
  31	 * Lockless access is OK, because file->private data is set
  32	 * once during mount and is valid until the file is released.
  33	 */
  34	return ACCESS_ONCE(file->private_data);
  35}
  36
  37static void fuse_request_init(struct fuse_req *req, struct page **pages,
  38			      struct fuse_page_desc *page_descs,
  39			      unsigned npages)
  40{
  41	memset(req, 0, sizeof(*req));
  42	memset(pages, 0, sizeof(*pages) * npages);
  43	memset(page_descs, 0, sizeof(*page_descs) * npages);
  44	INIT_LIST_HEAD(&req->list);
  45	INIT_LIST_HEAD(&req->intr_entry);
  46	init_waitqueue_head(&req->waitq);
  47	atomic_set(&req->count, 1);
  48	req->pages = pages;
  49	req->page_descs = page_descs;
  50	req->max_pages = npages;
  51	__set_bit(FR_PENDING, &req->flags);
 
  52}
  53
  54static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
  55{
  56	struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
  57	if (req) {
  58		struct page **pages;
  59		struct fuse_page_desc *page_descs;
  60
  61		if (npages <= FUSE_REQ_INLINE_PAGES) {
  62			pages = req->inline_pages;
  63			page_descs = req->inline_page_descs;
  64		} else {
  65			pages = kmalloc(sizeof(struct page *) * npages, flags);
  66			page_descs = kmalloc(sizeof(struct fuse_page_desc) *
  67					     npages, flags);
  68		}
  69
  70		if (!pages || !page_descs) {
  71			kfree(pages);
  72			kfree(page_descs);
  73			kmem_cache_free(fuse_req_cachep, req);
  74			return NULL;
  75		}
  76
  77		fuse_request_init(req, pages, page_descs, npages);
  78	}
  79	return req;
  80}
  81
  82struct fuse_req *fuse_request_alloc(unsigned npages)
  83{
  84	return __fuse_request_alloc(npages, GFP_KERNEL);
  85}
  86EXPORT_SYMBOL_GPL(fuse_request_alloc);
  87
  88struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
  89{
  90	return __fuse_request_alloc(npages, GFP_NOFS);
  91}
  92
  93void fuse_request_free(struct fuse_req *req)
  94{
  95	if (req->pages != req->inline_pages) {
  96		kfree(req->pages);
  97		kfree(req->page_descs);
  98	}
  99	kmem_cache_free(fuse_req_cachep, req);
 100}
 101
 102static void block_sigs(sigset_t *oldset)
 103{
 104	sigset_t mask;
 105
 106	siginitsetinv(&mask, sigmask(SIGKILL));
 107	sigprocmask(SIG_BLOCK, &mask, oldset);
 108}
 109
 110static void restore_sigs(sigset_t *oldset)
 111{
 112	sigprocmask(SIG_SETMASK, oldset, NULL);
 113}
 114
 115void __fuse_get_request(struct fuse_req *req)
 116{
 117	atomic_inc(&req->count);
 118}
 119
 120/* Must be called with > 1 refcount */
 121static void __fuse_put_request(struct fuse_req *req)
 122{
 123	BUG_ON(atomic_read(&req->count) < 2);
 124	atomic_dec(&req->count);
 125}
 126
 127static void fuse_req_init_context(struct fuse_req *req)
 128{
 129	req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
 130	req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
 131	req->in.h.pid = current->pid;
 132}
 133
 134void fuse_set_initialized(struct fuse_conn *fc)
 135{
 136	/* Make sure stores before this are seen on another CPU */
 137	smp_wmb();
 138	fc->initialized = 1;
 139}
 140
 141static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
 142{
 143	return !fc->initialized || (for_background && fc->blocked);
 144}
 145
 146static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
 147				       bool for_background)
 148{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 149	struct fuse_req *req;
 
 
 
 150	int err;
 
 151	atomic_inc(&fc->num_waiting);
 152
 153	if (fuse_block_alloc(fc, for_background)) {
 154		sigset_t oldset;
 155		int intr;
 156
 157		block_sigs(&oldset);
 158		intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
 159				!fuse_block_alloc(fc, for_background));
 160		restore_sigs(&oldset);
 161		err = -EINTR;
 162		if (intr)
 
 163			goto out;
 164	}
 165	/* Matches smp_wmb() in fuse_set_initialized() */
 166	smp_rmb();
 167
 168	err = -ENOTCONN;
 169	if (!fc->connected)
 170		goto out;
 171
 172	err = -ECONNREFUSED;
 173	if (fc->conn_error)
 174		goto out;
 175
 176	req = fuse_request_alloc(npages);
 177	err = -ENOMEM;
 178	if (!req) {
 179		if (for_background)
 180			wake_up(&fc->blocked_waitq);
 181		goto out;
 182	}
 183
 184	fuse_req_init_context(req);
 
 185	__set_bit(FR_WAITING, &req->flags);
 186	if (for_background)
 187		__set_bit(FR_BACKGROUND, &req->flags);
 188
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 189	return req;
 190
 191 out:
 192	atomic_dec(&fc->num_waiting);
 193	return ERR_PTR(err);
 194}
 195
 196struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
 197{
 198	return __fuse_get_req(fc, npages, false);
 199}
 200EXPORT_SYMBOL_GPL(fuse_get_req);
 201
 202struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
 203					     unsigned npages)
 204{
 205	return __fuse_get_req(fc, npages, true);
 206}
 207EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
 208
 209/*
 210 * Return request in fuse_file->reserved_req.  However that may
 211 * currently be in use.  If that is the case, wait for it to become
 212 * available.
 213 */
 214static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
 215					 struct file *file)
 216{
 217	struct fuse_req *req = NULL;
 218	struct fuse_file *ff = file->private_data;
 219
 220	do {
 221		wait_event(fc->reserved_req_waitq, ff->reserved_req);
 222		spin_lock(&fc->lock);
 223		if (ff->reserved_req) {
 224			req = ff->reserved_req;
 225			ff->reserved_req = NULL;
 226			req->stolen_file = get_file(file);
 227		}
 228		spin_unlock(&fc->lock);
 229	} while (!req);
 230
 231	return req;
 232}
 233
 234/*
 235 * Put stolen request back into fuse_file->reserved_req
 236 */
 237static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
 238{
 239	struct file *file = req->stolen_file;
 240	struct fuse_file *ff = file->private_data;
 241
 242	spin_lock(&fc->lock);
 243	fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
 244	BUG_ON(ff->reserved_req);
 245	ff->reserved_req = req;
 246	wake_up_all(&fc->reserved_req_waitq);
 247	spin_unlock(&fc->lock);
 248	fput(file);
 249}
 250
 251/*
 252 * Gets a requests for a file operation, always succeeds
 253 *
 254 * This is used for sending the FLUSH request, which must get to
 255 * userspace, due to POSIX locks which may need to be unlocked.
 256 *
 257 * If allocation fails due to OOM, use the reserved request in
 258 * fuse_file.
 259 *
 260 * This is very unlikely to deadlock accidentally, since the
 261 * filesystem should not have it's own file open.  If deadlock is
 262 * intentional, it can still be broken by "aborting" the filesystem.
 263 */
 264struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 265					     struct file *file)
 266{
 267	struct fuse_req *req;
 268
 269	atomic_inc(&fc->num_waiting);
 270	wait_event(fc->blocked_waitq, fc->initialized);
 271	/* Matches smp_wmb() in fuse_set_initialized() */
 272	smp_rmb();
 273	req = fuse_request_alloc(0);
 274	if (!req)
 275		req = get_reserved_req(fc, file);
 276
 277	fuse_req_init_context(req);
 278	__set_bit(FR_WAITING, &req->flags);
 279	__clear_bit(FR_BACKGROUND, &req->flags);
 280	return req;
 281}
 282
 283void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
 284{
 285	if (atomic_dec_and_test(&req->count)) {
 286		if (test_bit(FR_BACKGROUND, &req->flags)) {
 287			/*
 288			 * We get here in the unlikely case that a background
 289			 * request was allocated but not sent
 290			 */
 291			spin_lock(&fc->lock);
 292			if (!fc->blocked)
 293				wake_up(&fc->blocked_waitq);
 294			spin_unlock(&fc->lock);
 295		}
 296
 297		if (test_bit(FR_WAITING, &req->flags)) {
 298			__clear_bit(FR_WAITING, &req->flags);
 299			atomic_dec(&fc->num_waiting);
 300		}
 301
 302		if (req->stolen_file)
 303			put_reserved_req(fc, req);
 304		else
 305			fuse_request_free(req);
 306	}
 307}
 308EXPORT_SYMBOL_GPL(fuse_put_request);
 309
 310static unsigned len_args(unsigned numargs, struct fuse_arg *args)
 311{
 312	unsigned nbytes = 0;
 313	unsigned i;
 314
 315	for (i = 0; i < numargs; i++)
 316		nbytes += args[i].size;
 317
 318	return nbytes;
 319}
 
 320
 321static u64 fuse_get_unique(struct fuse_iqueue *fiq)
 322{
 323	return ++fiq->reqctr;
 
 324}
 325
 326static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
 327{
 328	req->in.h.len = sizeof(struct fuse_in_header) +
 329		len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
 330	list_add_tail(&req->list, &fiq->pending);
 331	wake_up_locked(&fiq->waitq);
 332	kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
 
 
 333}
 
 334
 335void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 336		       u64 nodeid, u64 nlookup)
 337{
 338	struct fuse_iqueue *fiq = &fc->iq;
 
 339
 340	forget->forget_one.nodeid = nodeid;
 341	forget->forget_one.nlookup = nlookup;
 
 
 
 
 
 
 
 
 342
 343	spin_lock(&fiq->waitq.lock);
 
 
 344	if (fiq->connected) {
 345		fiq->forget_list_tail->next = forget;
 346		fiq->forget_list_tail = forget;
 347		wake_up_locked(&fiq->waitq);
 348		kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
 349	} else {
 350		kfree(forget);
 
 351	}
 352	spin_unlock(&fiq->waitq.lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 353}
 354
 355static void flush_bg_queue(struct fuse_conn *fc)
 356{
 
 
 357	while (fc->active_background < fc->max_background &&
 358	       !list_empty(&fc->bg_queue)) {
 359		struct fuse_req *req;
 360		struct fuse_iqueue *fiq = &fc->iq;
 361
 362		req = list_entry(fc->bg_queue.next, struct fuse_req, list);
 363		list_del(&req->list);
 364		fc->active_background++;
 365		spin_lock(&fiq->waitq.lock);
 366		req->in.h.unique = fuse_get_unique(fiq);
 367		queue_request(fiq, req);
 368		spin_unlock(&fiq->waitq.lock);
 369	}
 370}
 371
 372/*
 373 * This function is called when a request is finished.  Either a reply
 374 * has arrived or it was aborted (and not yet sent) or some error
 375 * occurred during communication with userspace, or the device file
 376 * was closed.  The requester thread is woken up (if still waiting),
 377 * the 'end' callback is called if given, else the reference to the
 378 * request is released
 379 */
 380static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 381{
 
 
 382	struct fuse_iqueue *fiq = &fc->iq;
 383
 384	if (test_and_set_bit(FR_FINISHED, &req->flags))
 385		return;
 386
 387	spin_lock(&fiq->waitq.lock);
 388	list_del_init(&req->intr_entry);
 389	spin_unlock(&fiq->waitq.lock);
 
 
 
 
 
 
 
 
 390	WARN_ON(test_bit(FR_PENDING, &req->flags));
 391	WARN_ON(test_bit(FR_SENT, &req->flags));
 392	if (test_bit(FR_BACKGROUND, &req->flags)) {
 393		spin_lock(&fc->lock);
 394		clear_bit(FR_BACKGROUND, &req->flags);
 395		if (fc->num_background == fc->max_background)
 396			fc->blocked = 0;
 397
 398		/* Wake up next waiter, if any */
 399		if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
 400			wake_up(&fc->blocked_waitq);
 401
 402		if (fc->num_background == fc->congestion_threshold &&
 403		    fc->connected && fc->bdi_initialized) {
 404			clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
 405			clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
 
 
 
 
 406		}
 
 407		fc->num_background--;
 408		fc->active_background--;
 409		flush_bg_queue(fc);
 410		spin_unlock(&fc->lock);
 
 
 
 411	}
 412	wake_up(&req->waitq);
 413	if (req->end)
 414		req->end(fc, req);
 415	fuse_put_request(fc, req);
 
 416}
 
 417
 418static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
 419{
 420	spin_lock(&fiq->waitq.lock);
 421	if (list_empty(&req->intr_entry)) {
 422		list_add_tail(&req->intr_entry, &fiq->interrupts);
 423		wake_up_locked(&fiq->waitq);
 424	}
 425	spin_unlock(&fiq->waitq.lock);
 426	kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
 
 
 427}
 428
 429static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 430{
 
 431	struct fuse_iqueue *fiq = &fc->iq;
 432	int err;
 433
 434	if (!fc->no_interrupt) {
 435		/* Any signal may interrupt this */
 436		err = wait_event_interruptible(req->waitq,
 437					test_bit(FR_FINISHED, &req->flags));
 438		if (!err)
 439			return;
 440
 441		set_bit(FR_INTERRUPTED, &req->flags);
 442		/* matches barrier in fuse_dev_do_read() */
 443		smp_mb__after_atomic();
 444		if (test_bit(FR_SENT, &req->flags))
 445			queue_interrupt(fiq, req);
 446	}
 447
 448	if (!test_bit(FR_FORCE, &req->flags)) {
 449		sigset_t oldset;
 450
 451		/* Only fatal signals may interrupt this */
 452		block_sigs(&oldset);
 453		err = wait_event_interruptible(req->waitq,
 454					test_bit(FR_FINISHED, &req->flags));
 455		restore_sigs(&oldset);
 456
 457		if (!err)
 458			return;
 459
 460		spin_lock(&fiq->waitq.lock);
 461		/* Request is not yet in userspace, bail out */
 462		if (test_bit(FR_PENDING, &req->flags)) {
 463			list_del(&req->list);
 464			spin_unlock(&fiq->waitq.lock);
 465			__fuse_put_request(req);
 466			req->out.h.error = -EINTR;
 467			return;
 468		}
 469		spin_unlock(&fiq->waitq.lock);
 470	}
 471
 472	/*
 473	 * Either request is already in userspace, or it was forced.
 474	 * Wait it out.
 475	 */
 476	wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
 477}
 478
 479static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 480{
 481	struct fuse_iqueue *fiq = &fc->iq;
 482
 483	BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
 484	spin_lock(&fiq->waitq.lock);
 485	if (!fiq->connected) {
 486		spin_unlock(&fiq->waitq.lock);
 487		req->out.h.error = -ENOTCONN;
 488	} else {
 489		req->in.h.unique = fuse_get_unique(fiq);
 490		queue_request(fiq, req);
 491		/* acquire extra reference, since request is still needed
 492		   after request_end() */
 493		__fuse_get_request(req);
 494		spin_unlock(&fiq->waitq.lock);
 495
 496		request_wait_answer(fc, req);
 497		/* Pairs with smp_wmb() in request_end() */
 498		smp_rmb();
 499	}
 500}
 501
 502void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 503{
 504	__set_bit(FR_ISREPLY, &req->flags);
 505	if (!test_bit(FR_WAITING, &req->flags)) {
 506		__set_bit(FR_WAITING, &req->flags);
 507		atomic_inc(&fc->num_waiting);
 508	}
 509	__fuse_request_send(fc, req);
 510}
 511EXPORT_SYMBOL_GPL(fuse_request_send);
 512
 513static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
 514{
 515	if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
 516		args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
 517
 518	if (fc->minor < 9) {
 519		switch (args->in.h.opcode) {
 520		case FUSE_LOOKUP:
 521		case FUSE_CREATE:
 522		case FUSE_MKNOD:
 523		case FUSE_MKDIR:
 524		case FUSE_SYMLINK:
 525		case FUSE_LINK:
 526			args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
 527			break;
 528		case FUSE_GETATTR:
 529		case FUSE_SETATTR:
 530			args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
 531			break;
 532		}
 533	}
 534	if (fc->minor < 12) {
 535		switch (args->in.h.opcode) {
 536		case FUSE_CREATE:
 537			args->in.args[0].size = sizeof(struct fuse_open_in);
 538			break;
 539		case FUSE_MKNOD:
 540			args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
 541			break;
 542		}
 543	}
 544}
 545
 546ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 547{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 548	struct fuse_req *req;
 549	ssize_t ret;
 550
 551	req = fuse_get_req(fc, 0);
 552	if (IS_ERR(req))
 553		return PTR_ERR(req);
 
 
 
 
 
 
 
 
 
 
 
 
 554
 555	/* Needs to be done after fuse_get_req() so that fc->minor is valid */
 556	fuse_adjust_compat(fc, args);
 
 557
 558	req->in.h.opcode = args->in.h.opcode;
 559	req->in.h.nodeid = args->in.h.nodeid;
 560	req->in.numargs = args->in.numargs;
 561	memcpy(req->in.args, args->in.args,
 562	       args->in.numargs * sizeof(struct fuse_in_arg));
 563	req->out.argvar = args->out.argvar;
 564	req->out.numargs = args->out.numargs;
 565	memcpy(req->out.args, args->out.args,
 566	       args->out.numargs * sizeof(struct fuse_arg));
 567	fuse_request_send(fc, req);
 568	ret = req->out.h.error;
 569	if (!ret && args->out.argvar) {
 570		BUG_ON(args->out.numargs != 1);
 571		ret = req->out.args[0].size;
 572	}
 573	fuse_put_request(fc, req);
 574
 575	return ret;
 576}
 577
 578/*
 579 * Called under fc->lock
 580 *
 581 * fc->connected must have been checked previously
 582 */
 583void fuse_request_send_background_locked(struct fuse_conn *fc,
 584					 struct fuse_req *req)
 585{
 586	BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));
 
 
 
 
 587	if (!test_bit(FR_WAITING, &req->flags)) {
 588		__set_bit(FR_WAITING, &req->flags);
 589		atomic_inc(&fc->num_waiting);
 590	}
 591	__set_bit(FR_ISREPLY, &req->flags);
 592	fc->num_background++;
 593	if (fc->num_background == fc->max_background)
 594		fc->blocked = 1;
 595	if (fc->num_background == fc->congestion_threshold &&
 596	    fc->bdi_initialized) {
 597		set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
 598		set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
 
 599	}
 600	list_add_tail(&req->list, &fc->bg_queue);
 601	flush_bg_queue(fc);
 
 602}
 603
 604void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
 
 605{
 606	BUG_ON(!req->end);
 607	spin_lock(&fc->lock);
 608	if (fc->connected) {
 609		fuse_request_send_background_locked(fc, req);
 610		spin_unlock(&fc->lock);
 
 
 
 611	} else {
 612		spin_unlock(&fc->lock);
 613		req->out.h.error = -ENOTCONN;
 614		req->end(fc, req);
 615		fuse_put_request(fc, req);
 616	}
 617}
 618EXPORT_SYMBOL_GPL(fuse_request_send_background);
 619
 620static int fuse_request_send_notify_reply(struct fuse_conn *fc,
 621					  struct fuse_req *req, u64 unique)
 622{
 623	int err = -ENODEV;
 624	struct fuse_iqueue *fiq = &fc->iq;
 625
 626	__clear_bit(FR_ISREPLY, &req->flags);
 627	req->in.h.unique = unique;
 628	spin_lock(&fiq->waitq.lock);
 629	if (fiq->connected) {
 630		queue_request(fiq, req);
 631		err = 0;
 632	}
 633	spin_unlock(&fiq->waitq.lock);
 634
 635	return err;
 636}
 
 637
 638void fuse_force_forget(struct file *file, u64 nodeid)
 
 639{
 640	struct inode *inode = file_inode(file);
 641	struct fuse_conn *fc = get_fuse_conn(inode);
 642	struct fuse_req *req;
 643	struct fuse_forget_in inarg;
 
 
 
 
 644
 645	memset(&inarg, 0, sizeof(inarg));
 646	inarg.nlookup = 1;
 647	req = fuse_get_req_nofail_nopages(fc, file);
 648	req->in.h.opcode = FUSE_FORGET;
 649	req->in.h.nodeid = nodeid;
 650	req->in.numargs = 1;
 651	req->in.args[0].size = sizeof(inarg);
 652	req->in.args[0].value = &inarg;
 653	__clear_bit(FR_ISREPLY, &req->flags);
 654	__fuse_request_send(fc, req);
 655	/* ignore errors */
 656	fuse_put_request(fc, req);
 
 
 
 
 657}
 658
 659/*
 660 * Lock the request.  Up to the next unlock_request() there mustn't be
 661 * anything that could cause a page-fault.  If the request was already
 662 * aborted bail out.
 663 */
 664static int lock_request(struct fuse_req *req)
 665{
 666	int err = 0;
 667	if (req) {
 668		spin_lock(&req->waitq.lock);
 669		if (test_bit(FR_ABORTED, &req->flags))
 670			err = -ENOENT;
 671		else
 672			set_bit(FR_LOCKED, &req->flags);
 673		spin_unlock(&req->waitq.lock);
 674	}
 675	return err;
 676}
 677
 678/*
 679 * Unlock request.  If it was aborted while locked, caller is responsible
 680 * for unlocking and ending the request.
 681 */
 682static int unlock_request(struct fuse_req *req)
 683{
 684	int err = 0;
 685	if (req) {
 686		spin_lock(&req->waitq.lock);
 687		if (test_bit(FR_ABORTED, &req->flags))
 688			err = -ENOENT;
 689		else
 690			clear_bit(FR_LOCKED, &req->flags);
 691		spin_unlock(&req->waitq.lock);
 692	}
 693	return err;
 694}
 695
 696struct fuse_copy_state {
 697	int write;
 698	struct fuse_req *req;
 699	struct iov_iter *iter;
 700	struct pipe_buffer *pipebufs;
 701	struct pipe_buffer *currbuf;
 702	struct pipe_inode_info *pipe;
 703	unsigned long nr_segs;
 704	struct page *pg;
 705	unsigned len;
 706	unsigned offset;
 707	unsigned move_pages:1;
 708};
 709
 710static void fuse_copy_init(struct fuse_copy_state *cs, int write,
 711			   struct iov_iter *iter)
 712{
 713	memset(cs, 0, sizeof(*cs));
 714	cs->write = write;
 715	cs->iter = iter;
 716}
 717
 718/* Unmap and put previous page of userspace buffer */
 719static void fuse_copy_finish(struct fuse_copy_state *cs)
 720{
 721	if (cs->currbuf) {
 722		struct pipe_buffer *buf = cs->currbuf;
 723
 724		if (cs->write)
 725			buf->len = PAGE_SIZE - cs->len;
 726		cs->currbuf = NULL;
 727	} else if (cs->pg) {
 728		if (cs->write) {
 729			flush_dcache_page(cs->pg);
 730			set_page_dirty_lock(cs->pg);
 731		}
 732		put_page(cs->pg);
 733	}
 734	cs->pg = NULL;
 735}
 736
 737/*
 738 * Get another pagefull of userspace buffer, and map it to kernel
 739 * address space, and lock request
 740 */
 741static int fuse_copy_fill(struct fuse_copy_state *cs)
 742{
 743	struct page *page;
 744	int err;
 745
 746	err = unlock_request(cs->req);
 747	if (err)
 748		return err;
 749
 750	fuse_copy_finish(cs);
 751	if (cs->pipebufs) {
 752		struct pipe_buffer *buf = cs->pipebufs;
 753
 754		if (!cs->write) {
 755			err = buf->ops->confirm(cs->pipe, buf);
 756			if (err)
 757				return err;
 758
 759			BUG_ON(!cs->nr_segs);
 760			cs->currbuf = buf;
 761			cs->pg = buf->page;
 762			cs->offset = buf->offset;
 763			cs->len = buf->len;
 764			cs->pipebufs++;
 765			cs->nr_segs--;
 766		} else {
 767			if (cs->nr_segs == cs->pipe->buffers)
 768				return -EIO;
 769
 770			page = alloc_page(GFP_HIGHUSER);
 771			if (!page)
 772				return -ENOMEM;
 773
 774			buf->page = page;
 775			buf->offset = 0;
 776			buf->len = 0;
 777
 778			cs->currbuf = buf;
 779			cs->pg = page;
 780			cs->offset = 0;
 781			cs->len = PAGE_SIZE;
 782			cs->pipebufs++;
 783			cs->nr_segs++;
 784		}
 785	} else {
 786		size_t off;
 787		err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
 788		if (err < 0)
 789			return err;
 790		BUG_ON(!err);
 791		cs->len = err;
 792		cs->offset = off;
 793		cs->pg = page;
 794		cs->offset = off;
 795		iov_iter_advance(cs->iter, err);
 796	}
 797
 798	return lock_request(cs->req);
 799}
 800
 801/* Do as much copy to/from userspace buffer as we can */
 802static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
 803{
 804	unsigned ncpy = min(*size, cs->len);
 805	if (val) {
 806		void *pgaddr = kmap_atomic(cs->pg);
 807		void *buf = pgaddr + cs->offset;
 808
 809		if (cs->write)
 810			memcpy(buf, *val, ncpy);
 811		else
 812			memcpy(*val, buf, ncpy);
 813
 814		kunmap_atomic(pgaddr);
 815		*val += ncpy;
 816	}
 817	*size -= ncpy;
 818	cs->len -= ncpy;
 819	cs->offset += ncpy;
 820	return ncpy;
 821}
 822
 823static int fuse_check_page(struct page *page)
 824{
 825	if (page_mapcount(page) ||
 826	    page->mapping != NULL ||
 827	    page_count(page) != 1 ||
 828	    (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
 829	     ~(1 << PG_locked |
 830	       1 << PG_referenced |
 831	       1 << PG_uptodate |
 832	       1 << PG_lru |
 833	       1 << PG_active |
 834	       1 << PG_reclaim))) {
 835		printk(KERN_WARNING "fuse: trying to steal weird page\n");
 836		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);
 
 
 837		return 1;
 838	}
 839	return 0;
 840}
 841
 
 
 
 
 
 
 842static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
 843{
 844	int err;
 845	struct page *oldpage = *pagep;
 846	struct page *newpage;
 847	struct pipe_buffer *buf = cs->pipebufs;
 848
 
 849	err = unlock_request(cs->req);
 850	if (err)
 851		return err;
 852
 853	fuse_copy_finish(cs);
 854
 855	err = buf->ops->confirm(cs->pipe, buf);
 856	if (err)
 857		return err;
 858
 859	BUG_ON(!cs->nr_segs);
 860	cs->currbuf = buf;
 861	cs->len = buf->len;
 862	cs->pipebufs++;
 863	cs->nr_segs--;
 864
 865	if (cs->len != PAGE_SIZE)
 866		goto out_fallback;
 867
 868	if (buf->ops->steal(cs->pipe, buf) != 0)
 869		goto out_fallback;
 870
 871	newpage = buf->page;
 872
 873	if (!PageUptodate(newpage))
 874		SetPageUptodate(newpage);
 875
 876	ClearPageMappedToDisk(newpage);
 877
 878	if (fuse_check_page(newpage) != 0)
 879		goto out_fallback_unlock;
 880
 881	/*
 882	 * This is a new and locked page, it shouldn't be mapped or
 883	 * have any special flags on it
 884	 */
 885	if (WARN_ON(page_mapped(oldpage)))
 886		goto out_fallback_unlock;
 887	if (WARN_ON(page_has_private(oldpage)))
 888		goto out_fallback_unlock;
 889	if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
 
 890		goto out_fallback_unlock;
 891	if (WARN_ON(PageMlocked(oldpage)))
 892		goto out_fallback_unlock;
 893
 894	err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
 895	if (err) {
 896		unlock_page(newpage);
 897		return err;
 898	}
 899
 900	get_page(newpage);
 901
 902	if (!(buf->flags & PIPE_BUF_FLAG_LRU))
 903		lru_cache_add_file(newpage);
 
 
 
 
 
 
 904
 905	err = 0;
 906	spin_lock(&cs->req->waitq.lock);
 907	if (test_bit(FR_ABORTED, &cs->req->flags))
 908		err = -ENOENT;
 909	else
 910		*pagep = newpage;
 911	spin_unlock(&cs->req->waitq.lock);
 912
 913	if (err) {
 914		unlock_page(newpage);
 915		put_page(newpage);
 916		return err;
 917	}
 918
 919	unlock_page(oldpage);
 920	put_page(oldpage);
 
 921	cs->len = 0;
 922
 923	return 0;
 
 
 
 
 924
 925out_fallback_unlock:
 926	unlock_page(newpage);
 927out_fallback:
 928	cs->pg = buf->page;
 929	cs->offset = buf->offset;
 930
 931	err = lock_request(cs->req);
 932	if (err)
 933		return err;
 934
 935	return 1;
 936}
 937
 938static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
 939			 unsigned offset, unsigned count)
 940{
 941	struct pipe_buffer *buf;
 942	int err;
 943
 944	if (cs->nr_segs == cs->pipe->buffers)
 945		return -EIO;
 946
 
 947	err = unlock_request(cs->req);
 948	if (err)
 
 949		return err;
 
 950
 951	fuse_copy_finish(cs);
 952
 953	buf = cs->pipebufs;
 954	get_page(page);
 955	buf->page = page;
 956	buf->offset = offset;
 957	buf->len = count;
 958
 959	cs->pipebufs++;
 960	cs->nr_segs++;
 961	cs->len = 0;
 962
 963	return 0;
 964}
 965
 966/*
 967 * Copy a page in the request to/from the userspace buffer.  Must be
 968 * done atomically
 969 */
 970static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
 971			  unsigned offset, unsigned count, int zeroing)
 972{
 973	int err;
 974	struct page *page = *pagep;
 975
 976	if (page && zeroing && count < PAGE_SIZE)
 977		clear_highpage(page);
 978
 979	while (count) {
 980		if (cs->write && cs->pipebufs && page) {
 981			return fuse_ref_page(cs, page, offset, count);
 
 
 
 
 
 
 
 
 
 
 982		} else if (!cs->len) {
 983			if (cs->move_pages && page &&
 984			    offset == 0 && count == PAGE_SIZE) {
 985				err = fuse_try_move_page(cs, pagep);
 986				if (err <= 0)
 987					return err;
 988			} else {
 989				err = fuse_copy_fill(cs);
 990				if (err)
 991					return err;
 992			}
 993		}
 994		if (page) {
 995			void *mapaddr = kmap_atomic(page);
 996			void *buf = mapaddr + offset;
 997			offset += fuse_copy_do(cs, &buf, &count);
 998			kunmap_atomic(mapaddr);
 999		} else
1000			offset += fuse_copy_do(cs, NULL, &count);
1001	}
1002	if (page && !cs->write)
1003		flush_dcache_page(page);
1004	return 0;
1005}
1006
1007/* Copy pages in the request to/from userspace buffer */
1008static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1009			   int zeroing)
1010{
1011	unsigned i;
1012	struct fuse_req *req = cs->req;
 
1013
1014	for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
1015		int err;
1016		unsigned offset = req->page_descs[i].offset;
1017		unsigned count = min(nbytes, req->page_descs[i].length);
 
1018
1019		err = fuse_copy_page(cs, &req->pages[i], offset, count,
1020				     zeroing);
 
1021		if (err)
1022			return err;
1023
1024		nbytes -= count;
 
 
 
 
 
 
 
 
1025	}
1026	return 0;
1027}
1028
1029/* Copy a single argument in the request to/from userspace buffer */
1030static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1031{
1032	while (size) {
1033		if (!cs->len) {
1034			int err = fuse_copy_fill(cs);
1035			if (err)
1036				return err;
1037		}
1038		fuse_copy_do(cs, &val, &size);
1039	}
1040	return 0;
1041}
1042
1043/* Copy request arguments to/from userspace buffer */
1044static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1045			  unsigned argpages, struct fuse_arg *args,
1046			  int zeroing)
1047{
1048	int err = 0;
1049	unsigned i;
1050
1051	for (i = 0; !err && i < numargs; i++)  {
1052		struct fuse_arg *arg = &args[i];
1053		if (i == numargs - 1 && argpages)
1054			err = fuse_copy_pages(cs, arg->size, zeroing);
1055		else
1056			err = fuse_copy_one(cs, arg->value, arg->size);
1057	}
1058	return err;
1059}
1060
1061static int forget_pending(struct fuse_iqueue *fiq)
1062{
1063	return fiq->forget_list_head.next != NULL;
1064}
1065
1066static int request_pending(struct fuse_iqueue *fiq)
1067{
1068	return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
1069		forget_pending(fiq);
1070}
1071
1072/*
1073 * Transfer an interrupt request to userspace
1074 *
1075 * Unlike other requests this is assembled on demand, without a need
1076 * to allocate a separate fuse_req structure.
1077 *
1078 * Called with fiq->waitq.lock held, releases it
1079 */
1080static int fuse_read_interrupt(struct fuse_iqueue *fiq,
1081			       struct fuse_copy_state *cs,
1082			       size_t nbytes, struct fuse_req *req)
1083__releases(fiq->waitq.lock)
1084{
1085	struct fuse_in_header ih;
1086	struct fuse_interrupt_in arg;
1087	unsigned reqsize = sizeof(ih) + sizeof(arg);
1088	int err;
1089
1090	list_del_init(&req->intr_entry);
1091	req->intr_unique = fuse_get_unique(fiq);
1092	memset(&ih, 0, sizeof(ih));
1093	memset(&arg, 0, sizeof(arg));
1094	ih.len = reqsize;
1095	ih.opcode = FUSE_INTERRUPT;
1096	ih.unique = req->intr_unique;
1097	arg.unique = req->in.h.unique;
1098
1099	spin_unlock(&fiq->waitq.lock);
1100	if (nbytes < reqsize)
1101		return -EINVAL;
1102
1103	err = fuse_copy_one(cs, &ih, sizeof(ih));
1104	if (!err)
1105		err = fuse_copy_one(cs, &arg, sizeof(arg));
1106	fuse_copy_finish(cs);
1107
1108	return err ? err : reqsize;
1109}
1110
1111static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
1112					       unsigned max,
1113					       unsigned *countp)
1114{
1115	struct fuse_forget_link *head = fiq->forget_list_head.next;
1116	struct fuse_forget_link **newhead = &head;
1117	unsigned count;
1118
1119	for (count = 0; *newhead != NULL && count < max; count++)
1120		newhead = &(*newhead)->next;
1121
1122	fiq->forget_list_head.next = *newhead;
1123	*newhead = NULL;
1124	if (fiq->forget_list_head.next == NULL)
1125		fiq->forget_list_tail = &fiq->forget_list_head;
1126
1127	if (countp != NULL)
1128		*countp = count;
1129
1130	return head;
1131}
1132
1133static int fuse_read_single_forget(struct fuse_iqueue *fiq,
1134				   struct fuse_copy_state *cs,
1135				   size_t nbytes)
1136__releases(fiq->waitq.lock)
1137{
1138	int err;
1139	struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
1140	struct fuse_forget_in arg = {
1141		.nlookup = forget->forget_one.nlookup,
1142	};
1143	struct fuse_in_header ih = {
1144		.opcode = FUSE_FORGET,
1145		.nodeid = forget->forget_one.nodeid,
1146		.unique = fuse_get_unique(fiq),
1147		.len = sizeof(ih) + sizeof(arg),
1148	};
1149
1150	spin_unlock(&fiq->waitq.lock);
1151	kfree(forget);
1152	if (nbytes < ih.len)
1153		return -EINVAL;
1154
1155	err = fuse_copy_one(cs, &ih, sizeof(ih));
1156	if (!err)
1157		err = fuse_copy_one(cs, &arg, sizeof(arg));
1158	fuse_copy_finish(cs);
1159
1160	if (err)
1161		return err;
1162
1163	return ih.len;
1164}
1165
1166static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
1167				   struct fuse_copy_state *cs, size_t nbytes)
1168__releases(fiq->waitq.lock)
1169{
1170	int err;
1171	unsigned max_forgets;
1172	unsigned count;
1173	struct fuse_forget_link *head;
1174	struct fuse_batch_forget_in arg = { .count = 0 };
1175	struct fuse_in_header ih = {
1176		.opcode = FUSE_BATCH_FORGET,
1177		.unique = fuse_get_unique(fiq),
1178		.len = sizeof(ih) + sizeof(arg),
1179	};
1180
1181	if (nbytes < ih.len) {
1182		spin_unlock(&fiq->waitq.lock);
1183		return -EINVAL;
1184	}
1185
1186	max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1187	head = dequeue_forget(fiq, max_forgets, &count);
1188	spin_unlock(&fiq->waitq.lock);
1189
1190	arg.count = count;
1191	ih.len += count * sizeof(struct fuse_forget_one);
1192	err = fuse_copy_one(cs, &ih, sizeof(ih));
1193	if (!err)
1194		err = fuse_copy_one(cs, &arg, sizeof(arg));
1195
1196	while (head) {
1197		struct fuse_forget_link *forget = head;
1198
1199		if (!err) {
1200			err = fuse_copy_one(cs, &forget->forget_one,
1201					    sizeof(forget->forget_one));
1202		}
1203		head = forget->next;
1204		kfree(forget);
1205	}
1206
1207	fuse_copy_finish(cs);
1208
1209	if (err)
1210		return err;
1211
1212	return ih.len;
1213}
1214
1215static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
1216			    struct fuse_copy_state *cs,
1217			    size_t nbytes)
1218__releases(fiq->waitq.lock)
1219{
1220	if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
1221		return fuse_read_single_forget(fiq, cs, nbytes);
1222	else
1223		return fuse_read_batch_forget(fiq, cs, nbytes);
1224}
1225
1226/*
1227 * Read a single request into the userspace filesystem's buffer.  This
1228 * function waits until a request is available, then removes it from
1229 * the pending list and copies request data to userspace buffer.  If
1230 * no reply is needed (FORGET) or request has been aborted or there
1231 * was an error during the copying then it's finished by calling
1232 * request_end().  Otherwise add it to the processing list, and set
1233 * the 'sent' flag.
1234 */
1235static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
1236				struct fuse_copy_state *cs, size_t nbytes)
1237{
1238	ssize_t err;
1239	struct fuse_conn *fc = fud->fc;
1240	struct fuse_iqueue *fiq = &fc->iq;
1241	struct fuse_pqueue *fpq = &fud->pq;
1242	struct fuse_req *req;
1243	struct fuse_in *in;
1244	unsigned reqsize;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1245
1246 restart:
1247	spin_lock(&fiq->waitq.lock);
1248	err = -EAGAIN;
1249	if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
1250	    !request_pending(fiq))
1251		goto err_unlock;
1252
1253	err = wait_event_interruptible_exclusive_locked(fiq->waitq,
 
 
1254				!fiq->connected || request_pending(fiq));
1255	if (err)
1256		goto err_unlock;
 
1257
1258	err = -ENODEV;
1259	if (!fiq->connected)
1260		goto err_unlock;
 
1261
1262	if (!list_empty(&fiq->interrupts)) {
1263		req = list_entry(fiq->interrupts.next, struct fuse_req,
1264				 intr_entry);
1265		return fuse_read_interrupt(fiq, cs, nbytes, req);
1266	}
1267
1268	if (forget_pending(fiq)) {
1269		if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
1270			return fuse_read_forget(fc, fiq, cs, nbytes);
1271
1272		if (fiq->forget_batch <= -8)
1273			fiq->forget_batch = 16;
1274	}
1275
1276	req = list_entry(fiq->pending.next, struct fuse_req, list);
1277	clear_bit(FR_PENDING, &req->flags);
1278	list_del_init(&req->list);
1279	spin_unlock(&fiq->waitq.lock);
 
 
 
1280
1281	in = &req->in;
1282	reqsize = in->h.len;
1283	/* If request is too large, reply with an error and restart the read */
1284	if (nbytes < reqsize) {
1285		req->out.h.error = -EIO;
1286		/* SETXATTR is special, since it may contain too large data */
1287		if (in->h.opcode == FUSE_SETXATTR)
1288			req->out.h.error = -E2BIG;
1289		request_end(fc, req);
1290		goto restart;
1291	}
1292	spin_lock(&fpq->lock);
 
 
 
 
 
 
 
 
 
1293	list_add(&req->list, &fpq->io);
1294	spin_unlock(&fpq->lock);
1295	cs->req = req;
1296	err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1297	if (!err)
1298		err = fuse_copy_args(cs, in->numargs, in->argpages,
1299				     (struct fuse_arg *) in->args, 0);
1300	fuse_copy_finish(cs);
1301	spin_lock(&fpq->lock);
1302	clear_bit(FR_LOCKED, &req->flags);
1303	if (!fpq->connected) {
1304		err = -ENODEV;
1305		goto out_end;
1306	}
1307	if (err) {
1308		req->out.h.error = -EIO;
1309		goto out_end;
1310	}
1311	if (!test_bit(FR_ISREPLY, &req->flags)) {
1312		err = reqsize;
1313		goto out_end;
1314	}
1315	list_move_tail(&req->list, &fpq->processing);
1316	spin_unlock(&fpq->lock);
 
1317	set_bit(FR_SENT, &req->flags);
 
1318	/* matches barrier in request_wait_answer() */
1319	smp_mb__after_atomic();
1320	if (test_bit(FR_INTERRUPTED, &req->flags))
1321		queue_interrupt(fiq, req);
 
1322
1323	return reqsize;
1324
1325out_end:
1326	if (!test_bit(FR_PRIVATE, &req->flags))
1327		list_del_init(&req->list);
1328	spin_unlock(&fpq->lock);
1329	request_end(fc, req);
1330	return err;
1331
1332 err_unlock:
1333	spin_unlock(&fiq->waitq.lock);
1334	return err;
1335}
1336
1337static int fuse_dev_open(struct inode *inode, struct file *file)
1338{
1339	/*
1340	 * The fuse device's file's private_data is used to hold
1341	 * the fuse_conn(ection) when it is mounted, and is used to
1342	 * keep track of whether the file has been mounted already.
1343	 */
1344	file->private_data = NULL;
1345	return 0;
1346}
1347
1348static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
1349{
1350	struct fuse_copy_state cs;
1351	struct file *file = iocb->ki_filp;
1352	struct fuse_dev *fud = fuse_get_dev(file);
1353
1354	if (!fud)
1355		return -EPERM;
1356
1357	if (!iter_is_iovec(to))
1358		return -EINVAL;
1359
1360	fuse_copy_init(&cs, 1, to);
1361
1362	return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
1363}
1364
1365static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1366				    struct pipe_inode_info *pipe,
1367				    size_t len, unsigned int flags)
1368{
1369	int ret;
1370	int page_nr = 0;
1371	int do_wakeup = 0;
1372	struct pipe_buffer *bufs;
1373	struct fuse_copy_state cs;
1374	struct fuse_dev *fud = fuse_get_dev(in);
1375
1376	if (!fud)
1377		return -EPERM;
1378
1379	bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
 
1380	if (!bufs)
1381		return -ENOMEM;
1382
1383	fuse_copy_init(&cs, 1, NULL);
1384	cs.pipebufs = bufs;
1385	cs.pipe = pipe;
1386	ret = fuse_dev_do_read(fud, in, &cs, len);
1387	if (ret < 0)
1388		goto out;
1389
1390	ret = 0;
1391	pipe_lock(pipe);
1392
1393	if (!pipe->readers) {
1394		send_sig(SIGPIPE, current, 0);
1395		if (!ret)
1396			ret = -EPIPE;
1397		goto out_unlock;
1398	}
1399
1400	if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1401		ret = -EIO;
1402		goto out_unlock;
1403	}
1404
1405	while (page_nr < cs.nr_segs) {
1406		int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1407		struct pipe_buffer *buf = pipe->bufs + newbuf;
1408
1409		buf->page = bufs[page_nr].page;
1410		buf->offset = bufs[page_nr].offset;
1411		buf->len = bufs[page_nr].len;
1412		/*
1413		 * Need to be careful about this.  Having buf->ops in module
1414		 * code can Oops if the buffer persists after module unload.
1415		 */
1416		buf->ops = &nosteal_pipe_buf_ops;
1417
1418		pipe->nrbufs++;
1419		page_nr++;
1420		ret += buf->len;
1421
1422		if (pipe->files)
1423			do_wakeup = 1;
1424	}
1425
1426out_unlock:
1427	pipe_unlock(pipe);
1428
1429	if (do_wakeup) {
1430		smp_mb();
1431		if (waitqueue_active(&pipe->wait))
1432			wake_up_interruptible(&pipe->wait);
1433		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1434	}
1435
 
1436out:
1437	for (; page_nr < cs.nr_segs; page_nr++)
1438		put_page(bufs[page_nr].page);
1439
1440	kfree(bufs);
1441	return ret;
1442}
1443
1444static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1445			    struct fuse_copy_state *cs)
1446{
1447	struct fuse_notify_poll_wakeup_out outarg;
1448	int err = -EINVAL;
1449
1450	if (size != sizeof(outarg))
1451		goto err;
1452
1453	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1454	if (err)
1455		goto err;
1456
1457	fuse_copy_finish(cs);
1458	return fuse_notify_poll_wakeup(fc, &outarg);
1459
1460err:
1461	fuse_copy_finish(cs);
1462	return err;
1463}
1464
1465static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1466				   struct fuse_copy_state *cs)
1467{
1468	struct fuse_notify_inval_inode_out outarg;
1469	int err = -EINVAL;
1470
1471	if (size != sizeof(outarg))
1472		goto err;
1473
1474	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1475	if (err)
1476		goto err;
1477	fuse_copy_finish(cs);
1478
1479	down_read(&fc->killsb);
1480	err = -ENOENT;
1481	if (fc->sb) {
1482		err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1483					       outarg.off, outarg.len);
1484	}
1485	up_read(&fc->killsb);
1486	return err;
1487
1488err:
1489	fuse_copy_finish(cs);
1490	return err;
1491}
1492
1493static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1494				   struct fuse_copy_state *cs)
1495{
1496	struct fuse_notify_inval_entry_out outarg;
1497	int err = -ENOMEM;
1498	char *buf;
1499	struct qstr name;
1500
1501	buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1502	if (!buf)
1503		goto err;
1504
1505	err = -EINVAL;
1506	if (size < sizeof(outarg))
1507		goto err;
1508
1509	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1510	if (err)
1511		goto err;
1512
1513	err = -ENAMETOOLONG;
1514	if (outarg.namelen > FUSE_NAME_MAX)
1515		goto err;
1516
1517	err = -EINVAL;
1518	if (size != sizeof(outarg) + outarg.namelen + 1)
1519		goto err;
1520
1521	name.name = buf;
1522	name.len = outarg.namelen;
1523	err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1524	if (err)
1525		goto err;
1526	fuse_copy_finish(cs);
1527	buf[outarg.namelen] = 0;
1528	name.hash = full_name_hash(name.name, name.len);
1529
1530	down_read(&fc->killsb);
1531	err = -ENOENT;
1532	if (fc->sb)
1533		err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1534	up_read(&fc->killsb);
1535	kfree(buf);
1536	return err;
1537
1538err:
1539	kfree(buf);
1540	fuse_copy_finish(cs);
1541	return err;
1542}
1543
1544static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1545			      struct fuse_copy_state *cs)
1546{
1547	struct fuse_notify_delete_out outarg;
1548	int err = -ENOMEM;
1549	char *buf;
1550	struct qstr name;
1551
1552	buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1553	if (!buf)
1554		goto err;
1555
1556	err = -EINVAL;
1557	if (size < sizeof(outarg))
1558		goto err;
1559
1560	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1561	if (err)
1562		goto err;
1563
1564	err = -ENAMETOOLONG;
1565	if (outarg.namelen > FUSE_NAME_MAX)
1566		goto err;
1567
1568	err = -EINVAL;
1569	if (size != sizeof(outarg) + outarg.namelen + 1)
1570		goto err;
1571
1572	name.name = buf;
1573	name.len = outarg.namelen;
1574	err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1575	if (err)
1576		goto err;
1577	fuse_copy_finish(cs);
1578	buf[outarg.namelen] = 0;
1579	name.hash = full_name_hash(name.name, name.len);
1580
1581	down_read(&fc->killsb);
1582	err = -ENOENT;
1583	if (fc->sb)
1584		err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1585					       outarg.child, &name);
1586	up_read(&fc->killsb);
1587	kfree(buf);
1588	return err;
1589
1590err:
1591	kfree(buf);
1592	fuse_copy_finish(cs);
1593	return err;
1594}
1595
1596static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1597			     struct fuse_copy_state *cs)
1598{
1599	struct fuse_notify_store_out outarg;
1600	struct inode *inode;
1601	struct address_space *mapping;
1602	u64 nodeid;
1603	int err;
1604	pgoff_t index;
1605	unsigned int offset;
1606	unsigned int num;
1607	loff_t file_size;
1608	loff_t end;
1609
1610	err = -EINVAL;
1611	if (size < sizeof(outarg))
1612		goto out_finish;
1613
1614	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1615	if (err)
1616		goto out_finish;
1617
1618	err = -EINVAL;
1619	if (size - sizeof(outarg) != outarg.size)
1620		goto out_finish;
1621
1622	nodeid = outarg.nodeid;
1623
1624	down_read(&fc->killsb);
1625
1626	err = -ENOENT;
1627	if (!fc->sb)
1628		goto out_up_killsb;
1629
1630	inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1631	if (!inode)
1632		goto out_up_killsb;
1633
1634	mapping = inode->i_mapping;
1635	index = outarg.offset >> PAGE_SHIFT;
1636	offset = outarg.offset & ~PAGE_MASK;
1637	file_size = i_size_read(inode);
1638	end = outarg.offset + outarg.size;
1639	if (end > file_size) {
1640		file_size = end;
1641		fuse_write_update_size(inode, file_size);
1642	}
1643
1644	num = outarg.size;
1645	while (num) {
 
1646		struct page *page;
1647		unsigned int this_num;
1648
1649		err = -ENOMEM;
1650		page = find_or_create_page(mapping, index,
1651					   mapping_gfp_mask(mapping));
1652		if (!page)
1653			goto out_iput;
1654
1655		this_num = min_t(unsigned, num, PAGE_SIZE - offset);
 
1656		err = fuse_copy_page(cs, &page, offset, this_num, 0);
1657		if (!err && offset == 0 &&
1658		    (this_num == PAGE_SIZE || file_size == end))
1659			SetPageUptodate(page);
1660		unlock_page(page);
1661		put_page(page);
 
 
1662
1663		if (err)
1664			goto out_iput;
1665
1666		num -= this_num;
1667		offset = 0;
1668		index++;
1669	}
1670
1671	err = 0;
1672
1673out_iput:
1674	iput(inode);
1675out_up_killsb:
1676	up_read(&fc->killsb);
1677out_finish:
1678	fuse_copy_finish(cs);
1679	return err;
1680}
1681
1682static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
 
 
 
 
 
 
1683{
1684	release_pages(req->pages, req->num_pages, false);
 
 
 
 
1685}
1686
1687static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1688			 struct fuse_notify_retrieve_out *outarg)
1689{
1690	int err;
1691	struct address_space *mapping = inode->i_mapping;
1692	struct fuse_req *req;
1693	pgoff_t index;
1694	loff_t file_size;
1695	unsigned int num;
1696	unsigned int offset;
1697	size_t total_len = 0;
1698	int num_pages;
 
 
 
 
 
1699
1700	offset = outarg->offset & ~PAGE_MASK;
1701	file_size = i_size_read(inode);
1702
1703	num = outarg->size;
1704	if (outarg->offset > file_size)
1705		num = 0;
1706	else if (outarg->offset + num > file_size)
1707		num = file_size - outarg->offset;
1708
1709	num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1710	num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1711
1712	req = fuse_get_req(fc, num_pages);
1713	if (IS_ERR(req))
1714		return PTR_ERR(req);
1715
1716	req->in.h.opcode = FUSE_NOTIFY_REPLY;
1717	req->in.h.nodeid = outarg->nodeid;
1718	req->in.numargs = 2;
1719	req->in.argpages = 1;
1720	req->page_descs[0].offset = offset;
1721	req->end = fuse_retrieve_end;
 
 
 
 
 
 
 
 
1722
1723	index = outarg->offset >> PAGE_SHIFT;
1724
1725	while (num && req->num_pages < num_pages) {
1726		struct page *page;
1727		unsigned int this_num;
1728
1729		page = find_get_page(mapping, index);
1730		if (!page)
1731			break;
1732
1733		this_num = min_t(unsigned, num, PAGE_SIZE - offset);
1734		req->pages[req->num_pages] = page;
1735		req->page_descs[req->num_pages].length = this_num;
1736		req->num_pages++;
 
 
1737
1738		offset = 0;
1739		num -= this_num;
1740		total_len += this_num;
1741		index++;
1742	}
1743	req->misc.retrieve_in.offset = outarg->offset;
1744	req->misc.retrieve_in.size = total_len;
1745	req->in.args[0].size = sizeof(req->misc.retrieve_in);
1746	req->in.args[0].value = &req->misc.retrieve_in;
1747	req->in.args[1].size = total_len;
1748
1749	err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1750	if (err)
1751		fuse_retrieve_end(fc, req);
1752
1753	return err;
1754}
1755
1756static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1757				struct fuse_copy_state *cs)
1758{
1759	struct fuse_notify_retrieve_out outarg;
 
1760	struct inode *inode;
 
1761	int err;
1762
1763	err = -EINVAL;
1764	if (size != sizeof(outarg))
1765		goto copy_finish;
1766
1767	err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1768	if (err)
1769		goto copy_finish;
1770
1771	fuse_copy_finish(cs);
1772
1773	down_read(&fc->killsb);
1774	err = -ENOENT;
1775	if (fc->sb) {
1776		u64 nodeid = outarg.nodeid;
1777
1778		inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1779		if (inode) {
1780			err = fuse_retrieve(fc, inode, &outarg);
1781			iput(inode);
1782		}
1783	}
1784	up_read(&fc->killsb);
1785
1786	return err;
1787
1788copy_finish:
1789	fuse_copy_finish(cs);
1790	return err;
1791}
1792
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1793static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1794		       unsigned int size, struct fuse_copy_state *cs)
1795{
1796	/* Don't try to move pages (yet) */
1797	cs->move_pages = 0;
1798
1799	switch (code) {
1800	case FUSE_NOTIFY_POLL:
1801		return fuse_notify_poll(fc, size, cs);
1802
1803	case FUSE_NOTIFY_INVAL_INODE:
1804		return fuse_notify_inval_inode(fc, size, cs);
1805
1806	case FUSE_NOTIFY_INVAL_ENTRY:
1807		return fuse_notify_inval_entry(fc, size, cs);
1808
1809	case FUSE_NOTIFY_STORE:
1810		return fuse_notify_store(fc, size, cs);
1811
1812	case FUSE_NOTIFY_RETRIEVE:
1813		return fuse_notify_retrieve(fc, size, cs);
1814
1815	case FUSE_NOTIFY_DELETE:
1816		return fuse_notify_delete(fc, size, cs);
1817
 
 
 
1818	default:
1819		fuse_copy_finish(cs);
1820		return -EINVAL;
1821	}
1822}
1823
1824/* Look up request on processing list by unique ID */
1825static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
1826{
 
1827	struct fuse_req *req;
1828
1829	list_for_each_entry(req, &fpq->processing, list) {
1830		if (req->in.h.unique == unique || req->intr_unique == unique)
1831			return req;
1832	}
1833	return NULL;
1834}
1835
1836static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1837			 unsigned nbytes)
1838{
1839	unsigned reqsize = sizeof(struct fuse_out_header);
1840
1841	if (out->h.error)
1842		return nbytes != reqsize ? -EINVAL : 0;
1843
1844	reqsize += len_args(out->numargs, out->args);
1845
1846	if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1847		return -EINVAL;
1848	else if (reqsize > nbytes) {
1849		struct fuse_arg *lastarg = &out->args[out->numargs-1];
1850		unsigned diffsize = reqsize - nbytes;
 
1851		if (diffsize > lastarg->size)
1852			return -EINVAL;
1853		lastarg->size -= diffsize;
1854	}
1855	return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1856			      out->page_zeroing);
1857}
1858
1859/*
1860 * Write a single reply to a request.  First the header is copied from
1861 * the write buffer.  The request is then searched on the processing
1862 * list by the unique ID found in the header.  If found, then remove
1863 * it from the list and copy the rest of the buffer to the request.
1864 * The request is finished by calling request_end()
1865 */
1866static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
1867				 struct fuse_copy_state *cs, size_t nbytes)
1868{
1869	int err;
1870	struct fuse_conn *fc = fud->fc;
1871	struct fuse_pqueue *fpq = &fud->pq;
1872	struct fuse_req *req;
1873	struct fuse_out_header oh;
1874
 
1875	if (nbytes < sizeof(struct fuse_out_header))
1876		return -EINVAL;
1877
1878	err = fuse_copy_one(cs, &oh, sizeof(oh));
1879	if (err)
1880		goto err_finish;
1881
1882	err = -EINVAL;
1883	if (oh.len != nbytes)
1884		goto err_finish;
1885
1886	/*
1887	 * Zero oh.unique indicates unsolicited notification message
1888	 * and error contains notification code.
1889	 */
1890	if (!oh.unique) {
1891		err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1892		return err ? err : nbytes;
1893	}
1894
1895	err = -EINVAL;
1896	if (oh.error <= -1000 || oh.error > 0)
1897		goto err_finish;
1898
1899	spin_lock(&fpq->lock);
1900	err = -ENOENT;
1901	if (!fpq->connected)
1902		goto err_unlock_pq;
1903
1904	req = request_find(fpq, oh.unique);
1905	if (!req)
1906		goto err_unlock_pq;
 
 
1907
1908	/* Is it an interrupt reply? */
1909	if (req->intr_unique == oh.unique) {
 
1910		spin_unlock(&fpq->lock);
1911
1912		err = -EINVAL;
1913		if (nbytes != sizeof(struct fuse_out_header))
1914			goto err_finish;
1915
1916		if (oh.error == -ENOSYS)
1917			fc->no_interrupt = 1;
1918		else if (oh.error == -EAGAIN)
1919			queue_interrupt(&fc->iq, req);
1920
1921		fuse_copy_finish(cs);
1922		return nbytes;
 
1923	}
1924
1925	clear_bit(FR_SENT, &req->flags);
1926	list_move(&req->list, &fpq->io);
1927	req->out.h = oh;
1928	set_bit(FR_LOCKED, &req->flags);
1929	spin_unlock(&fpq->lock);
1930	cs->req = req;
1931	if (!req->out.page_replace)
1932		cs->move_pages = 0;
1933
1934	err = copy_out_args(cs, &req->out, nbytes);
 
 
 
1935	fuse_copy_finish(cs);
1936
1937	spin_lock(&fpq->lock);
1938	clear_bit(FR_LOCKED, &req->flags);
1939	if (!fpq->connected)
1940		err = -ENOENT;
1941	else if (err)
1942		req->out.h.error = -EIO;
1943	if (!test_bit(FR_PRIVATE, &req->flags))
1944		list_del_init(&req->list);
1945	spin_unlock(&fpq->lock);
1946
1947	request_end(fc, req);
1948
1949	return err ? err : nbytes;
1950
1951 err_unlock_pq:
1952	spin_unlock(&fpq->lock);
1953 err_finish:
1954	fuse_copy_finish(cs);
1955	return err;
1956}
1957
1958static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
1959{
1960	struct fuse_copy_state cs;
1961	struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
1962
1963	if (!fud)
1964		return -EPERM;
1965
1966	if (!iter_is_iovec(from))
1967		return -EINVAL;
1968
1969	fuse_copy_init(&cs, 0, from);
1970
1971	return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
1972}
1973
1974static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1975				     struct file *out, loff_t *ppos,
1976				     size_t len, unsigned int flags)
1977{
 
1978	unsigned nbuf;
1979	unsigned idx;
1980	struct pipe_buffer *bufs;
1981	struct fuse_copy_state cs;
1982	struct fuse_dev *fud;
1983	size_t rem;
1984	ssize_t ret;
1985
1986	fud = fuse_get_dev(out);
1987	if (!fud)
1988		return -EPERM;
1989
1990	bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1991	if (!bufs)
 
 
 
 
 
 
 
 
1992		return -ENOMEM;
 
1993
1994	pipe_lock(pipe);
1995	nbuf = 0;
1996	rem = 0;
1997	for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1998		rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1999
2000	ret = -EINVAL;
2001	if (rem < len) {
2002		pipe_unlock(pipe);
2003		goto out;
2004	}
2005
2006	rem = len;
2007	while (rem) {
2008		struct pipe_buffer *ibuf;
2009		struct pipe_buffer *obuf;
2010
2011		BUG_ON(nbuf >= pipe->buffers);
2012		BUG_ON(!pipe->nrbufs);
2013		ibuf = &pipe->bufs[pipe->curbuf];
 
2014		obuf = &bufs[nbuf];
2015
2016		if (rem >= ibuf->len) {
2017			*obuf = *ibuf;
2018			ibuf->ops = NULL;
2019			pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2020			pipe->nrbufs--;
2021		} else {
2022			ibuf->ops->get(pipe, ibuf);
 
 
2023			*obuf = *ibuf;
2024			obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2025			obuf->len = rem;
2026			ibuf->offset += obuf->len;
2027			ibuf->len -= obuf->len;
2028		}
2029		nbuf++;
2030		rem -= obuf->len;
2031	}
2032	pipe_unlock(pipe);
2033
2034	fuse_copy_init(&cs, 0, NULL);
2035	cs.pipebufs = bufs;
2036	cs.nr_segs = nbuf;
2037	cs.pipe = pipe;
2038
2039	if (flags & SPLICE_F_MOVE)
2040		cs.move_pages = 1;
2041
2042	ret = fuse_dev_do_write(fud, &cs, len);
2043
 
 
2044	for (idx = 0; idx < nbuf; idx++) {
2045		struct pipe_buffer *buf = &bufs[idx];
2046		buf->ops->release(pipe, buf);
 
 
2047	}
2048out:
2049	kfree(bufs);
 
2050	return ret;
2051}
2052
2053static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
2054{
2055	unsigned mask = POLLOUT | POLLWRNORM;
2056	struct fuse_iqueue *fiq;
2057	struct fuse_dev *fud = fuse_get_dev(file);
2058
2059	if (!fud)
2060		return POLLERR;
2061
2062	fiq = &fud->fc->iq;
2063	poll_wait(file, &fiq->waitq, wait);
2064
2065	spin_lock(&fiq->waitq.lock);
2066	if (!fiq->connected)
2067		mask = POLLERR;
2068	else if (request_pending(fiq))
2069		mask |= POLLIN | POLLRDNORM;
2070	spin_unlock(&fiq->waitq.lock);
2071
2072	return mask;
2073}
2074
2075/*
2076 * Abort all requests on the given list (pending or processing)
2077 *
2078 * This function releases and reacquires fc->lock
2079 */
2080static void end_requests(struct fuse_conn *fc, struct list_head *head)
2081{
2082	while (!list_empty(head)) {
2083		struct fuse_req *req;
2084		req = list_entry(head->next, struct fuse_req, list);
2085		req->out.h.error = -ECONNABORTED;
2086		clear_bit(FR_PENDING, &req->flags);
2087		clear_bit(FR_SENT, &req->flags);
2088		list_del_init(&req->list);
2089		request_end(fc, req);
2090	}
2091}
2092
2093static void end_polls(struct fuse_conn *fc)
2094{
2095	struct rb_node *p;
2096
2097	p = rb_first(&fc->polled_files);
2098
2099	while (p) {
2100		struct fuse_file *ff;
2101		ff = rb_entry(p, struct fuse_file, polled_node);
2102		wake_up_interruptible_all(&ff->poll_wait);
2103
2104		p = rb_next(p);
2105	}
2106}
2107
2108/*
2109 * Abort all requests.
2110 *
2111 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2112 * filesystem.
2113 *
2114 * The same effect is usually achievable through killing the filesystem daemon
2115 * and all users of the filesystem.  The exception is the combination of an
2116 * asynchronous request and the tricky deadlock (see
2117 * Documentation/filesystems/fuse.txt).
2118 *
2119 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2120 * requests, they should be finished off immediately.  Locked requests will be
2121 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2122 * requests.  It is possible that some request will finish before we can.  This
2123 * is OK, the request will in that case be removed from the list before we touch
2124 * it.
2125 */
2126void fuse_abort_conn(struct fuse_conn *fc)
2127{
2128	struct fuse_iqueue *fiq = &fc->iq;
2129
2130	spin_lock(&fc->lock);
2131	if (fc->connected) {
2132		struct fuse_dev *fud;
2133		struct fuse_req *req, *next;
2134		LIST_HEAD(to_end1);
2135		LIST_HEAD(to_end2);
2136
 
 
2137		fc->connected = 0;
2138		fc->blocked = 0;
 
2139		fuse_set_initialized(fc);
2140		list_for_each_entry(fud, &fc->devices, entry) {
2141			struct fuse_pqueue *fpq = &fud->pq;
2142
2143			spin_lock(&fpq->lock);
2144			fpq->connected = 0;
2145			list_for_each_entry_safe(req, next, &fpq->io, list) {
2146				req->out.h.error = -ECONNABORTED;
2147				spin_lock(&req->waitq.lock);
2148				set_bit(FR_ABORTED, &req->flags);
2149				if (!test_bit(FR_LOCKED, &req->flags)) {
2150					set_bit(FR_PRIVATE, &req->flags);
2151					list_move(&req->list, &to_end1);
 
2152				}
2153				spin_unlock(&req->waitq.lock);
2154			}
2155			list_splice_init(&fpq->processing, &to_end2);
 
 
2156			spin_unlock(&fpq->lock);
2157		}
 
 
2158		fc->max_background = UINT_MAX;
2159		flush_bg_queue(fc);
 
2160
2161		spin_lock(&fiq->waitq.lock);
2162		fiq->connected = 0;
2163		list_splice_init(&fiq->pending, &to_end2);
 
 
2164		while (forget_pending(fiq))
2165			kfree(dequeue_forget(fiq, 1, NULL));
2166		wake_up_all_locked(&fiq->waitq);
2167		spin_unlock(&fiq->waitq.lock);
2168		kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
2169		end_polls(fc);
2170		wake_up_all(&fc->blocked_waitq);
2171		spin_unlock(&fc->lock);
2172
2173		while (!list_empty(&to_end1)) {
2174			req = list_first_entry(&to_end1, struct fuse_req, list);
2175			__fuse_get_request(req);
2176			list_del_init(&req->list);
2177			request_end(fc, req);
2178		}
2179		end_requests(fc, &to_end2);
2180	} else {
2181		spin_unlock(&fc->lock);
2182	}
2183}
2184EXPORT_SYMBOL_GPL(fuse_abort_conn);
2185
 
 
 
 
 
 
 
2186int fuse_dev_release(struct inode *inode, struct file *file)
2187{
2188	struct fuse_dev *fud = fuse_get_dev(file);
2189
2190	if (fud) {
2191		struct fuse_conn *fc = fud->fc;
2192		struct fuse_pqueue *fpq = &fud->pq;
 
 
2193
 
2194		WARN_ON(!list_empty(&fpq->io));
2195		end_requests(fc, &fpq->processing);
 
 
 
 
 
2196		/* Are we the last open device? */
2197		if (atomic_dec_and_test(&fc->dev_count)) {
2198			WARN_ON(fc->iq.fasync != NULL);
2199			fuse_abort_conn(fc);
2200		}
2201		fuse_dev_free(fud);
2202	}
2203	return 0;
2204}
2205EXPORT_SYMBOL_GPL(fuse_dev_release);
2206
2207static int fuse_dev_fasync(int fd, struct file *file, int on)
2208{
2209	struct fuse_dev *fud = fuse_get_dev(file);
2210
2211	if (!fud)
2212		return -EPERM;
2213
2214	/* No locking - fasync_helper does its own locking */
2215	return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
2216}
2217
2218static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
2219{
2220	struct fuse_dev *fud;
2221
2222	if (new->private_data)
2223		return -EINVAL;
2224
2225	fud = fuse_dev_alloc(fc);
2226	if (!fud)
2227		return -ENOMEM;
2228
2229	new->private_data = fud;
2230	atomic_inc(&fc->dev_count);
2231
2232	return 0;
2233}
2234
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2235static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
2236			   unsigned long arg)
2237{
2238	int err = -ENOTTY;
2239
2240	if (cmd == FUSE_DEV_IOC_CLONE) {
2241		int oldfd;
 
2242
2243		err = -EFAULT;
2244		if (!get_user(oldfd, (__u32 __user *) arg)) {
2245			struct file *old = fget(oldfd);
2246
2247			err = -EINVAL;
2248			if (old) {
2249				struct fuse_dev *fud = NULL;
2250
2251				/*
2252				 * Check against file->f_op because CUSE
2253				 * uses the same ioctl handler.
2254				 */
2255				if (old->f_op == file->f_op &&
2256				    old->f_cred->user_ns == file->f_cred->user_ns)
2257					fud = fuse_get_dev(old);
2258
2259				if (fud) {
2260					mutex_lock(&fuse_mutex);
2261					err = fuse_device_clone(fud->fc, file);
2262					mutex_unlock(&fuse_mutex);
2263				}
2264				fput(old);
2265			}
2266		}
2267	}
2268	return err;
2269}
2270
2271const struct file_operations fuse_dev_operations = {
2272	.owner		= THIS_MODULE,
2273	.open		= fuse_dev_open,
2274	.llseek		= no_llseek,
2275	.read_iter	= fuse_dev_read,
2276	.splice_read	= fuse_dev_splice_read,
2277	.write_iter	= fuse_dev_write,
2278	.splice_write	= fuse_dev_splice_write,
2279	.poll		= fuse_dev_poll,
2280	.release	= fuse_dev_release,
2281	.fasync		= fuse_dev_fasync,
2282	.unlocked_ioctl = fuse_dev_ioctl,
2283	.compat_ioctl   = fuse_dev_ioctl,
2284};
2285EXPORT_SYMBOL_GPL(fuse_dev_operations);
2286
2287static struct miscdevice fuse_miscdevice = {
2288	.minor = FUSE_MINOR,
2289	.name  = "fuse",
2290	.fops = &fuse_dev_operations,
2291};
2292
2293int __init fuse_dev_init(void)
2294{
2295	int err = -ENOMEM;
2296	fuse_req_cachep = kmem_cache_create("fuse_request",
2297					    sizeof(struct fuse_req),
2298					    0, 0, NULL);
2299	if (!fuse_req_cachep)
2300		goto out;
2301
2302	err = misc_register(&fuse_miscdevice);
2303	if (err)
2304		goto out_cache_clean;
2305
2306	return 0;
2307
2308 out_cache_clean:
2309	kmem_cache_destroy(fuse_req_cachep);
2310 out:
2311	return err;
2312}
2313
2314void fuse_dev_cleanup(void)
2315{
2316	misc_deregister(&fuse_miscdevice);
2317	kmem_cache_destroy(fuse_req_cachep);
2318}