file.c 14.9 KB
Newer Older
M
Miklos Szeredi 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14
/*
  FUSE: Filesystem in Userspace
  Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>

  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#include "fuse_i.h"

#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/kernel.h>

15 16
static struct file_operations fuse_direct_io_file_operations;

M
Miklos Szeredi 已提交
17 18
static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
			  struct fuse_open_out *outargp)
M
Miklos Szeredi 已提交
19 20 21
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_open_in inarg;
M
Miklos Szeredi 已提交
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79
	struct fuse_req *req;
	int err;

	req = fuse_get_request(fc);
	if (!req)
		return -EINTR;

	memset(&inarg, 0, sizeof(inarg));
	inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
	req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(*outargp);
	req->out.args[0].value = outargp;
	request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);

	return err;
}

struct fuse_file *fuse_file_alloc(void)
{
	struct fuse_file *ff;
	ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
	if (ff) {
		ff->release_req = fuse_request_alloc();
		if (!ff->release_req) {
			kfree(ff);
			ff = NULL;
		}
	}
	return ff;
}

void fuse_file_free(struct fuse_file *ff)
{
	fuse_request_free(ff->release_req);
	kfree(ff);
}

void fuse_finish_open(struct inode *inode, struct file *file,
		      struct fuse_file *ff, struct fuse_open_out *outarg)
{
	if (outarg->open_flags & FOPEN_DIRECT_IO)
		file->f_op = &fuse_direct_io_file_operations;
	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
		invalidate_inode_pages(inode->i_mapping);
	ff->fh = outarg->fh;
	file->private_data = ff;
}

int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
M
Miklos Szeredi 已提交
80 81 82 83
	struct fuse_open_out outarg;
	struct fuse_file *ff;
	int err;

M
Miklos Szeredi 已提交
84 85 86 87
	/* VFS checks this, but only _after_ ->open() */
	if (file->f_flags & O_DIRECT)
		return -EINVAL;

M
Miklos Szeredi 已提交
88 89 90 91 92 93 94
	err = generic_file_open(inode, file);
	if (err)
		return err;

	/* If opening the root node, no lookup has been performed on
	   it, so the attributes must be refreshed */
	if (get_node_id(inode) == FUSE_ROOT_ID) {
M
Miklos Szeredi 已提交
95
		err = fuse_do_getattr(inode);
M
Miklos Szeredi 已提交
96 97 98 99
		if (err)
		 	return err;
	}

M
Miklos Szeredi 已提交
100
	ff = fuse_file_alloc();
M
Miklos Szeredi 已提交
101
	if (!ff)
M
Miklos Szeredi 已提交
102
		return -ENOMEM;
M
Miklos Szeredi 已提交
103

M
Miklos Szeredi 已提交
104 105 106 107 108 109 110
	err = fuse_send_open(inode, file, isdir, &outarg);
	if (err)
		fuse_file_free(ff);
	else {
		if (isdir)
			outarg.open_flags &= ~FOPEN_DIRECT_IO;
		fuse_finish_open(inode, file, ff, &outarg);
M
Miklos Szeredi 已提交
111 112 113 114 115
	}

	return err;
}

116 117 118 119 120 121 122 123
/* Special case for failed iget in CREATE */
static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
{
	u64 nodeid = req->in.h.nodeid;
	fuse_reset_request(req);
	fuse_send_forget(fc, req, nodeid, 1);
}

M
Miklos Szeredi 已提交
124 125
void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
		       u64 nodeid, struct inode *inode, int flags, int isdir)
M
Miklos Szeredi 已提交
126
{
M
Miklos Szeredi 已提交
127
	struct fuse_req * req = ff->release_req;
M
Miklos Szeredi 已提交
128 129 130
	struct fuse_release_in *inarg = &req->misc.release_in;

	inarg->fh = ff->fh;
M
Miklos Szeredi 已提交
131
	inarg->flags = flags;
132
	req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
M
Miklos Szeredi 已提交
133
	req->in.h.nodeid = nodeid;
M
Miklos Szeredi 已提交
134 135 136 137 138
	req->inode = inode;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_release_in);
	req->in.args[0].value = inarg;
	request_send_background(fc, req);
139 140
	if (!inode)
		req->end = fuse_release_end;
M
Miklos Szeredi 已提交
141
	kfree(ff);
M
Miklos Szeredi 已提交
142 143 144 145 146 147 148 149 150 151
}

int fuse_release_common(struct inode *inode, struct file *file, int isdir)
{
	struct fuse_file *ff = file->private_data;
	if (ff) {
		struct fuse_conn *fc = get_fuse_conn(inode);
		u64 nodeid = get_node_id(inode);
		fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
	}
M
Miklos Szeredi 已提交
152 153 154 155 156

	/* Return value is ignored by VFS */
	return 0;
}

157 158 159 160 161 162 163 164 165 166
static int fuse_open(struct inode *inode, struct file *file)
{
	return fuse_open_common(inode, file, 0);
}

static int fuse_release(struct inode *inode, struct file *file)
{
	return fuse_release_common(inode, file, 0);
}

M
Miklos Szeredi 已提交
167 168 169 170 171 172 173 174 175
static int fuse_flush(struct file *file)
{
	struct inode *inode = file->f_dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_flush_in inarg;
	int err;

176 177 178
	if (is_bad_inode(inode))
		return -EIO;

M
Miklos Szeredi 已提交
179 180 181
	if (fc->no_flush)
		return 0;

182
	req = fuse_get_request(fc);
M
Miklos Szeredi 已提交
183 184 185 186 187 188 189 190 191 192 193 194
	if (!req)
		return -EINTR;

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	req->in.h.opcode = FUSE_FLUSH;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
195
	request_send(fc, req);
M
Miklos Szeredi 已提交
196 197 198 199 200 201 202 203 204
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
		fc->no_flush = 1;
		err = 0;
	}
	return err;
}

205 206
int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
		      int isdir)
M
Miklos Szeredi 已提交
207 208 209 210 211 212 213 214
{
	struct inode *inode = de->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_req *req;
	struct fuse_fsync_in inarg;
	int err;

215 216 217
	if (is_bad_inode(inode))
		return -EIO;

218
	if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir))
M
Miklos Szeredi 已提交
219 220 221 222
		return 0;

	req = fuse_get_request(fc);
	if (!req)
223
		return -EINTR;
M
Miklos Szeredi 已提交
224 225 226 227

	memset(&inarg, 0, sizeof(inarg));
	inarg.fh = ff->fh;
	inarg.fsync_flags = datasync ? 1 : 0;
228
	req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC;
M
Miklos Szeredi 已提交
229 230 231 232 233 234 235 236 237 238
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(inarg);
	req->in.args[0].value = &inarg;
	request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (err == -ENOSYS) {
239 240 241 242
		if (isdir)
			fc->no_fsyncdir = 1;
		else
			fc->no_fsync = 1;
M
Miklos Szeredi 已提交
243 244 245 246 247
		err = 0;
	}
	return err;
}

248 249 250 251 252
static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
{
	return fuse_fsync_common(file, de, datasync, 0);
}

253 254
void fuse_read_fill(struct fuse_req *req, struct file *file,
		    struct inode *inode, loff_t pos, size_t count, int opcode)
M
Miklos Szeredi 已提交
255 256
{
	struct fuse_file *ff = file->private_data;
257
	struct fuse_read_in *inarg = &req->misc.read_in;
M
Miklos Szeredi 已提交
258

259 260 261 262
	inarg->fh = ff->fh;
	inarg->offset = pos;
	inarg->size = count;
	req->in.h.opcode = opcode;
M
Miklos Szeredi 已提交
263 264 265 266 267 268 269 270 271 272 273 274
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_read_in);
	req->in.args[0].value = &inarg;
	req->out.argpages = 1;
	req->out.argvar = 1;
	req->out.numargs = 1;
	req->out.args[0].size = count;
}

275 276
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
			     struct inode *inode, loff_t pos, size_t count)
277
{
278 279 280 281
	struct fuse_conn *fc = get_fuse_conn(inode);
	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
	request_send(fc, req);
	return req->out.args[0].size;
282 283
}

M
Miklos Szeredi 已提交
284 285 286 287
static int fuse_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
288 289 290 291 292 293 294 295 296
	struct fuse_req *req;
	int err;

	err = -EIO;
	if (is_bad_inode(inode))
		goto out;

	err = -EINTR;
	req = fuse_get_request(fc);
M
Miklos Szeredi 已提交
297 298 299 300 301 302
	if (!req)
		goto out;

	req->out.page_zeroing = 1;
	req->num_pages = 1;
	req->pages[0] = page;
303
	fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
M
Miklos Szeredi 已提交
304 305 306 307
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err)
		SetPageUptodate(page);
308
	fuse_invalidate_attr(inode); /* atime changed */
M
Miklos Szeredi 已提交
309 310 311 312 313
 out:
	unlock_page(page);
	return err;
}

314 315 316
static int fuse_send_readpages(struct fuse_req *req, struct file *file,
			       struct inode *inode)
{
317
	loff_t pos = page_offset(req->pages[0]);
318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366
	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
	unsigned i;
	req->out.page_zeroing = 1;
	fuse_send_read(req, file, inode, pos, count);
	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (!req->out.h.error)
			SetPageUptodate(page);
		unlock_page(page);
	}
	return req->out.h.error;
}

struct fuse_readpages_data {
	struct fuse_req *req;
	struct file *file;
	struct inode *inode;
};

static int fuse_readpages_fill(void *_data, struct page *page)
{
	struct fuse_readpages_data *data = _data;
	struct fuse_req *req = data->req;
	struct inode *inode = data->inode;
	struct fuse_conn *fc = get_fuse_conn(inode);

	if (req->num_pages &&
	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
	     req->pages[req->num_pages - 1]->index + 1 != page->index)) {
		int err = fuse_send_readpages(req, data->file, inode);
		if (err) {
			unlock_page(page);
			return err;
		}
		fuse_reset_request(req);
	}
	req->pages[req->num_pages] = page;
	req->num_pages ++;
	return 0;
}

static int fuse_readpages(struct file *file, struct address_space *mapping,
			  struct list_head *pages, unsigned nr_pages)
{
	struct inode *inode = mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_readpages_data data;
	int err;
367 368 369 370

	if (is_bad_inode(inode))
		return -EIO;

371 372
	data.file = file;
	data.inode = inode;
373
	data.req = fuse_get_request(fc);
374 375 376 377 378 379 380
	if (!data.req)
		return -EINTR;

	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
	if (!err && data.req->num_pages)
		err = fuse_send_readpages(data.req, file, inode);
	fuse_put_request(fc, data.req);
381
	fuse_invalidate_attr(inode); /* atime changed */
382 383 384
	return err;
}

385 386
static size_t fuse_send_write(struct fuse_req *req, struct file *file,
			      struct inode *inode, loff_t pos, size_t count)
M
Miklos Szeredi 已提交
387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_file *ff = file->private_data;
	struct fuse_write_in inarg;
	struct fuse_write_out outarg;

	memset(&inarg, 0, sizeof(struct fuse_write_in));
	inarg.fh = ff->fh;
	inarg.offset = pos;
	inarg.size = count;
	req->in.h.opcode = FUSE_WRITE;
	req->in.h.nodeid = get_node_id(inode);
	req->inode = inode;
	req->file = file;
	req->in.argpages = 1;
	req->in.numargs = 2;
	req->in.args[0].size = sizeof(struct fuse_write_in);
	req->in.args[0].value = &inarg;
	req->in.args[1].size = count;
	req->out.numargs = 1;
	req->out.args[0].size = sizeof(struct fuse_write_out);
	req->out.args[0].value = &outarg;
409
	request_send(fc, req);
M
Miklos Szeredi 已提交
410 411 412 413 414 415 416 417 418 419 420 421 422 423
	return outarg.size;
}

static int fuse_prepare_write(struct file *file, struct page *page,
			      unsigned offset, unsigned to)
{
	/* No op */
	return 0;
}

static int fuse_commit_write(struct file *file, struct page *page,
			     unsigned offset, unsigned to)
{
	int err;
424
	size_t nres;
M
Miklos Szeredi 已提交
425 426 427
	unsigned count = to - offset;
	struct inode *inode = page->mapping->host;
	struct fuse_conn *fc = get_fuse_conn(inode);
428
	loff_t pos = page_offset(page) + offset;
429 430 431 432 433 434
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

	req = fuse_get_request(fc);
M
Miklos Szeredi 已提交
435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454
	if (!req)
		return -EINTR;

	req->num_pages = 1;
	req->pages[0] = page;
	req->page_offset = offset;
	nres = fuse_send_write(req, file, inode, pos, count);
	err = req->out.h.error;
	fuse_put_request(fc, req);
	if (!err && nres != count)
		err = -EIO;
	if (!err) {
		pos += count;
		if (pos > i_size_read(inode))
			i_size_write(inode, pos);

		if (offset == 0 && to == PAGE_CACHE_SIZE) {
			clear_page_dirty(page);
			SetPageUptodate(page);
		}
455 456
	}
	fuse_invalidate_attr(inode);
M
Miklos Szeredi 已提交
457 458 459
	return err;
}

M
Miklos Szeredi 已提交
460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484
static void fuse_release_user_pages(struct fuse_req *req, int write)
{
	unsigned i;

	for (i = 0; i < req->num_pages; i++) {
		struct page *page = req->pages[i];
		if (write)
			set_page_dirty_lock(page);
		put_page(page);
	}
}

static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf,
			       unsigned nbytes, int write)
{
	unsigned long user_addr = (unsigned long) buf;
	unsigned offset = user_addr & ~PAGE_MASK;
	int npages;

	/* This doesn't work with nfsd */
	if (!current->mm)
		return -EPERM;

	nbytes = min(nbytes, (unsigned) FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT);
	npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
485
	npages = min(max(npages, 1), FUSE_MAX_PAGES_PER_REQ);
M
Miklos Szeredi 已提交
486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
	down_read(&current->mm->mmap_sem);
	npages = get_user_pages(current, current->mm, user_addr, npages, write,
				0, req->pages, NULL);
	up_read(&current->mm->mmap_sem);
	if (npages < 0)
		return npages;

	req->num_pages = npages;
	req->page_offset = offset;
	return 0;
}

static ssize_t fuse_direct_io(struct file *file, const char __user *buf,
			      size_t count, loff_t *ppos, int write)
{
	struct inode *inode = file->f_dentry->d_inode;
	struct fuse_conn *fc = get_fuse_conn(inode);
	size_t nmax = write ? fc->max_write : fc->max_read;
	loff_t pos = *ppos;
	ssize_t res = 0;
506 507 508 509 510 511
	struct fuse_req *req;

	if (is_bad_inode(inode))
		return -EIO;

	req = fuse_get_request(fc);
M
Miklos Szeredi 已提交
512
	if (!req)
513
		return -EINTR;
M
Miklos Szeredi 已提交
514 515 516 517 518 519 520 521 522

	while (count) {
		size_t nres;
		size_t nbytes = min(count, nmax);
		int err = fuse_get_user_pages(req, buf, nbytes, !write);
		if (err) {
			res = err;
			break;
		}
523 524
		nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
		nbytes = min(count, nbytes);
M
Miklos Szeredi 已提交
525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551
		if (write)
			nres = fuse_send_write(req, file, inode, pos, nbytes);
		else
			nres = fuse_send_read(req, file, inode, pos, nbytes);
		fuse_release_user_pages(req, !write);
		if (req->out.h.error) {
			if (!res)
				res = req->out.h.error;
			break;
		} else if (nres > nbytes) {
			res = -EIO;
			break;
		}
		count -= nres;
		res += nres;
		pos += nres;
		buf += nres;
		if (nres != nbytes)
			break;
		if (count)
			fuse_reset_request(req);
	}
	fuse_put_request(fc, req);
	if (res > 0) {
		if (write && pos > i_size_read(inode))
			i_size_write(inode, pos);
		*ppos = pos;
552 553
	}
	fuse_invalidate_attr(inode);
M
Miklos Szeredi 已提交
554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569

	return res;
}

static ssize_t fuse_direct_read(struct file *file, char __user *buf,
				     size_t count, loff_t *ppos)
{
	return fuse_direct_io(file, buf, count, ppos, 0);
}

static ssize_t fuse_direct_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
	struct inode *inode = file->f_dentry->d_inode;
	ssize_t res;
	/* Don't allow parallel writes to the same file */
570
	mutex_lock(&inode->i_mutex);
M
Miklos Szeredi 已提交
571
	res = fuse_direct_io(file, buf, count, ppos, 1);
572
	mutex_unlock(&inode->i_mutex);
M
Miklos Szeredi 已提交
573 574 575
	return res;
}

M
Miklos Szeredi 已提交
576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	if ((vma->vm_flags & VM_SHARED)) {
		if ((vma->vm_flags & VM_WRITE))
			return -ENODEV;
		else
			vma->vm_flags &= ~VM_MAYWRITE;
	}
	return generic_file_mmap(file, vma);
}

static int fuse_set_page_dirty(struct page *page)
{
	printk("fuse_set_page_dirty: should not happen\n");
	dump_stack();
	return 0;
}

static struct file_operations fuse_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_file_read,
	.write		= generic_file_write,
	.mmap		= fuse_file_mmap,
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
	.sendfile	= generic_file_sendfile,
};

M
Miklos Szeredi 已提交
606 607 608 609 610 611 612 613 614 615 616
static struct file_operations fuse_direct_io_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= fuse_direct_read,
	.write		= fuse_direct_write,
	.open		= fuse_open,
	.flush		= fuse_flush,
	.release	= fuse_release,
	.fsync		= fuse_fsync,
	/* no mmap and sendfile */
};

M
Miklos Szeredi 已提交
617 618 619 620
static struct address_space_operations fuse_file_aops  = {
	.readpage	= fuse_readpage,
	.prepare_write	= fuse_prepare_write,
	.commit_write	= fuse_commit_write,
621
	.readpages	= fuse_readpages,
M
Miklos Szeredi 已提交
622 623 624 625 626
	.set_page_dirty	= fuse_set_page_dirty,
};

void fuse_init_file_inode(struct inode *inode)
{
627 628
	inode->i_fop = &fuse_file_operations;
	inode->i_data.a_ops = &fuse_file_aops;
M
Miklos Szeredi 已提交
629
}