| 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/pagemap.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/compat.h> |
| 17 | #include <linux/swap.h> |
| 18 | |
| 19 | static const struct file_operations fuse_direct_io_file_operations; |
| 20 | |
| 21 | static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file, |
| 22 | int opcode, struct fuse_open_out *outargp) |
| 23 | { |
| 24 | struct fuse_open_in inarg; |
| 25 | struct fuse_req *req; |
| 26 | int err; |
| 27 | |
| 28 | req = fuse_get_req(fc); |
| 29 | if (IS_ERR(req)) |
| 30 | return PTR_ERR(req); |
| 31 | |
| 32 | memset(&inarg, 0, sizeof(inarg)); |
| 33 | inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY); |
| 34 | if (!fc->atomic_o_trunc) |
| 35 | inarg.flags &= ~O_TRUNC; |
| 36 | req->in.h.opcode = opcode; |
| 37 | req->in.h.nodeid = nodeid; |
| 38 | req->in.numargs = 1; |
| 39 | req->in.args[0].size = sizeof(inarg); |
| 40 | req->in.args[0].value = &inarg; |
| 41 | req->out.numargs = 1; |
| 42 | req->out.args[0].size = sizeof(*outargp); |
| 43 | req->out.args[0].value = outargp; |
| 44 | fuse_request_send(fc, req); |
| 45 | err = req->out.h.error; |
| 46 | fuse_put_request(fc, req); |
| 47 | |
| 48 | return err; |
| 49 | } |
| 50 | |
| 51 | struct fuse_file *fuse_file_alloc(struct fuse_conn *fc) |
| 52 | { |
| 53 | struct fuse_file *ff; |
| 54 | |
| 55 | ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL); |
| 56 | if (unlikely(!ff)) |
| 57 | return NULL; |
| 58 | |
| 59 | ff->fc = fc; |
| 60 | ff->reserved_req = fuse_request_alloc(); |
| 61 | if (unlikely(!ff->reserved_req)) { |
| 62 | kfree(ff); |
| 63 | return NULL; |
| 64 | } |
| 65 | |
| 66 | INIT_LIST_HEAD(&ff->write_entry); |
| 67 | atomic_set(&ff->count, 0); |
| 68 | RB_CLEAR_NODE(&ff->polled_node); |
| 69 | init_waitqueue_head(&ff->poll_wait); |
| 70 | |
| 71 | spin_lock(&fc->lock); |
| 72 | ff->kh = ++fc->khctr; |
| 73 | spin_unlock(&fc->lock); |
| 74 | |
| 75 | return ff; |
| 76 | } |
| 77 | |
| 78 | void fuse_file_free(struct fuse_file *ff) |
| 79 | { |
| 80 | fuse_request_free(ff->reserved_req); |
| 81 | kfree(ff); |
| 82 | } |
| 83 | |
| 84 | struct fuse_file *fuse_file_get(struct fuse_file *ff) |
| 85 | { |
| 86 | atomic_inc(&ff->count); |
| 87 | return ff; |
| 88 | } |
| 89 | |
| 90 | static void fuse_release_async(struct work_struct *work) |
| 91 | { |
| 92 | struct fuse_req *req; |
| 93 | struct fuse_conn *fc; |
| 94 | struct path path; |
| 95 | |
| 96 | req = container_of(work, struct fuse_req, misc.release.work); |
| 97 | path = req->misc.release.path; |
| 98 | fc = get_fuse_conn(path.dentry->d_inode); |
| 99 | |
| 100 | fuse_put_request(fc, req); |
| 101 | path_put(&path); |
| 102 | } |
| 103 | |
| 104 | static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req) |
| 105 | { |
| 106 | if (fc->destroy_req) { |
| 107 | /* |
| 108 | * If this is a fuseblk mount, then it's possible that |
| 109 | * releasing the path will result in releasing the |
| 110 | * super block and sending the DESTROY request. If |
| 111 | * the server is single threaded, this would hang. |
| 112 | * For this reason do the path_put() in a separate |
| 113 | * thread. |
| 114 | */ |
| 115 | atomic_inc(&req->count); |
| 116 | INIT_WORK(&req->misc.release.work, fuse_release_async); |
| 117 | schedule_work(&req->misc.release.work); |
| 118 | } else { |
| 119 | path_put(&req->misc.release.path); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | static void fuse_file_put(struct fuse_file *ff, bool sync) |
| 124 | { |
| 125 | if (atomic_dec_and_test(&ff->count)) { |
| 126 | struct fuse_req *req = ff->reserved_req; |
| 127 | |
| 128 | if (sync) { |
| 129 | fuse_request_send(ff->fc, req); |
| 130 | path_put(&req->misc.release.path); |
| 131 | fuse_put_request(ff->fc, req); |
| 132 | } else { |
| 133 | req->end = fuse_release_end; |
| 134 | fuse_request_send_background(ff->fc, req); |
| 135 | } |
| 136 | kfree(ff); |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file, |
| 141 | bool isdir) |
| 142 | { |
| 143 | struct fuse_open_out outarg; |
| 144 | struct fuse_file *ff; |
| 145 | int err; |
| 146 | int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN; |
| 147 | |
| 148 | ff = fuse_file_alloc(fc); |
| 149 | if (!ff) |
| 150 | return -ENOMEM; |
| 151 | |
| 152 | err = fuse_send_open(fc, nodeid, file, opcode, &outarg); |
| 153 | if (err) { |
| 154 | fuse_file_free(ff); |
| 155 | return err; |
| 156 | } |
| 157 | |
| 158 | if (isdir) |
| 159 | outarg.open_flags &= ~FOPEN_DIRECT_IO; |
| 160 | |
| 161 | ff->fh = outarg.fh; |
| 162 | ff->nodeid = nodeid; |
| 163 | ff->open_flags = outarg.open_flags; |
| 164 | file->private_data = fuse_file_get(ff); |
| 165 | |
| 166 | return 0; |
| 167 | } |
| 168 | EXPORT_SYMBOL_GPL(fuse_do_open); |
| 169 | |
| 170 | void fuse_finish_open(struct inode *inode, struct file *file) |
| 171 | { |
| 172 | struct fuse_file *ff = file->private_data; |
| 173 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 174 | |
| 175 | if (ff->open_flags & FOPEN_DIRECT_IO) |
| 176 | file->f_op = &fuse_direct_io_file_operations; |
| 177 | if (!(ff->open_flags & FOPEN_KEEP_CACHE)) |
| 178 | invalidate_inode_pages2(inode->i_mapping); |
| 179 | if (ff->open_flags & FOPEN_NONSEEKABLE) |
| 180 | nonseekable_open(inode, file); |
| 181 | if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) { |
| 182 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 183 | |
| 184 | spin_lock(&fc->lock); |
| 185 | fi->attr_version = ++fc->attr_version; |
| 186 | i_size_write(inode, 0); |
| 187 | spin_unlock(&fc->lock); |
| 188 | fuse_invalidate_attr(inode); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | int fuse_open_common(struct inode *inode, struct file *file, bool isdir) |
| 193 | { |
| 194 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 195 | int err; |
| 196 | |
| 197 | /* VFS checks this, but only _after_ ->open() */ |
| 198 | if (file->f_flags & O_DIRECT) |
| 199 | return -EINVAL; |
| 200 | |
| 201 | err = generic_file_open(inode, file); |
| 202 | if (err) |
| 203 | return err; |
| 204 | |
| 205 | err = fuse_do_open(fc, get_node_id(inode), file, isdir); |
| 206 | if (err) |
| 207 | return err; |
| 208 | |
| 209 | fuse_finish_open(inode, file); |
| 210 | |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | static void fuse_prepare_release(struct fuse_file *ff, int flags, int opcode) |
| 215 | { |
| 216 | struct fuse_conn *fc = ff->fc; |
| 217 | struct fuse_req *req = ff->reserved_req; |
| 218 | struct fuse_release_in *inarg = &req->misc.release.in; |
| 219 | |
| 220 | spin_lock(&fc->lock); |
| 221 | list_del(&ff->write_entry); |
| 222 | if (!RB_EMPTY_NODE(&ff->polled_node)) |
| 223 | rb_erase(&ff->polled_node, &fc->polled_files); |
| 224 | spin_unlock(&fc->lock); |
| 225 | |
| 226 | wake_up_interruptible_all(&ff->poll_wait); |
| 227 | |
| 228 | inarg->fh = ff->fh; |
| 229 | inarg->flags = flags; |
| 230 | req->in.h.opcode = opcode; |
| 231 | req->in.h.nodeid = ff->nodeid; |
| 232 | req->in.numargs = 1; |
| 233 | req->in.args[0].size = sizeof(struct fuse_release_in); |
| 234 | req->in.args[0].value = inarg; |
| 235 | } |
| 236 | |
| 237 | void fuse_release_common(struct file *file, int opcode) |
| 238 | { |
| 239 | struct fuse_file *ff; |
| 240 | struct fuse_req *req; |
| 241 | |
| 242 | ff = file->private_data; |
| 243 | if (unlikely(!ff)) |
| 244 | return; |
| 245 | |
| 246 | req = ff->reserved_req; |
| 247 | fuse_prepare_release(ff, file->f_flags, opcode); |
| 248 | |
| 249 | if (ff->flock) { |
| 250 | struct fuse_release_in *inarg = &req->misc.release.in; |
| 251 | inarg->release_flags |= FUSE_RELEASE_FLOCK_UNLOCK; |
| 252 | inarg->lock_owner = fuse_lock_owner_id(ff->fc, |
| 253 | (fl_owner_t) file); |
| 254 | } |
| 255 | /* Hold vfsmount and dentry until release is finished */ |
| 256 | path_get(&file->f_path); |
| 257 | req->misc.release.path = file->f_path; |
| 258 | |
| 259 | /* |
| 260 | * Normally this will send the RELEASE request, however if |
| 261 | * some asynchronous READ or WRITE requests are outstanding, |
| 262 | * the sending will be delayed. |
| 263 | * |
| 264 | * Make the release synchronous if this is a fuseblk mount, |
| 265 | * synchronous RELEASE is allowed (and desirable) in this case |
| 266 | * because the server can be trusted not to screw up. |
| 267 | */ |
| 268 | fuse_file_put(ff, ff->fc->destroy_req != NULL); |
| 269 | } |
| 270 | |
| 271 | static int fuse_open(struct inode *inode, struct file *file) |
| 272 | { |
| 273 | return fuse_open_common(inode, file, false); |
| 274 | } |
| 275 | |
| 276 | static int fuse_release(struct inode *inode, struct file *file) |
| 277 | { |
| 278 | fuse_release_common(file, FUSE_RELEASE); |
| 279 | |
| 280 | /* return value is ignored by VFS */ |
| 281 | return 0; |
| 282 | } |
| 283 | |
| 284 | void fuse_sync_release(struct fuse_file *ff, int flags) |
| 285 | { |
| 286 | WARN_ON(atomic_read(&ff->count) > 1); |
| 287 | fuse_prepare_release(ff, flags, FUSE_RELEASE); |
| 288 | ff->reserved_req->force = 1; |
| 289 | fuse_request_send(ff->fc, ff->reserved_req); |
| 290 | fuse_put_request(ff->fc, ff->reserved_req); |
| 291 | kfree(ff); |
| 292 | } |
| 293 | EXPORT_SYMBOL_GPL(fuse_sync_release); |
| 294 | |
| 295 | /* |
| 296 | * Scramble the ID space with XTEA, so that the value of the files_struct |
| 297 | * pointer is not exposed to userspace. |
| 298 | */ |
| 299 | u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id) |
| 300 | { |
| 301 | u32 *k = fc->scramble_key; |
| 302 | u64 v = (unsigned long) id; |
| 303 | u32 v0 = v; |
| 304 | u32 v1 = v >> 32; |
| 305 | u32 sum = 0; |
| 306 | int i; |
| 307 | |
| 308 | for (i = 0; i < 32; i++) { |
| 309 | v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]); |
| 310 | sum += 0x9E3779B9; |
| 311 | v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[sum>>11 & 3]); |
| 312 | } |
| 313 | |
| 314 | return (u64) v0 + ((u64) v1 << 32); |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * Check if page is under writeback |
| 319 | * |
| 320 | * This is currently done by walking the list of writepage requests |
| 321 | * for the inode, which can be pretty inefficient. |
| 322 | */ |
| 323 | static bool fuse_page_is_writeback(struct inode *inode, pgoff_t index) |
| 324 | { |
| 325 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 326 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 327 | struct fuse_req *req; |
| 328 | bool found = false; |
| 329 | |
| 330 | spin_lock(&fc->lock); |
| 331 | list_for_each_entry(req, &fi->writepages, writepages_entry) { |
| 332 | pgoff_t curr_index; |
| 333 | |
| 334 | BUG_ON(req->inode != inode); |
| 335 | curr_index = req->misc.write.in.offset >> PAGE_CACHE_SHIFT; |
| 336 | if (curr_index == index) { |
| 337 | found = true; |
| 338 | break; |
| 339 | } |
| 340 | } |
| 341 | spin_unlock(&fc->lock); |
| 342 | |
| 343 | return found; |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * Wait for page writeback to be completed. |
| 348 | * |
| 349 | * Since fuse doesn't rely on the VM writeback tracking, this has to |
| 350 | * use some other means. |
| 351 | */ |
| 352 | static int fuse_wait_on_page_writeback(struct inode *inode, pgoff_t index) |
| 353 | { |
| 354 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 355 | |
| 356 | wait_event(fi->page_waitq, !fuse_page_is_writeback(inode, index)); |
| 357 | return 0; |
| 358 | } |
| 359 | |
| 360 | static int fuse_flush(struct file *file, fl_owner_t id) |
| 361 | { |
| 362 | struct inode *inode = file->f_path.dentry->d_inode; |
| 363 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 364 | struct fuse_file *ff = file->private_data; |
| 365 | struct fuse_req *req; |
| 366 | struct fuse_flush_in inarg; |
| 367 | int err; |
| 368 | |
| 369 | if (is_bad_inode(inode)) |
| 370 | return -EIO; |
| 371 | |
| 372 | if (fc->no_flush) |
| 373 | return 0; |
| 374 | |
| 375 | req = fuse_get_req_nofail(fc, file); |
| 376 | memset(&inarg, 0, sizeof(inarg)); |
| 377 | inarg.fh = ff->fh; |
| 378 | inarg.lock_owner = fuse_lock_owner_id(fc, id); |
| 379 | req->in.h.opcode = FUSE_FLUSH; |
| 380 | req->in.h.nodeid = get_node_id(inode); |
| 381 | req->in.numargs = 1; |
| 382 | req->in.args[0].size = sizeof(inarg); |
| 383 | req->in.args[0].value = &inarg; |
| 384 | req->force = 1; |
| 385 | fuse_request_send(fc, req); |
| 386 | err = req->out.h.error; |
| 387 | fuse_put_request(fc, req); |
| 388 | if (err == -ENOSYS) { |
| 389 | fc->no_flush = 1; |
| 390 | err = 0; |
| 391 | } |
| 392 | return err; |
| 393 | } |
| 394 | |
| 395 | /* |
| 396 | * Wait for all pending writepages on the inode to finish. |
| 397 | * |
| 398 | * This is currently done by blocking further writes with FUSE_NOWRITE |
| 399 | * and waiting for all sent writes to complete. |
| 400 | * |
| 401 | * This must be called under i_mutex, otherwise the FUSE_NOWRITE usage |
| 402 | * could conflict with truncation. |
| 403 | */ |
| 404 | static void fuse_sync_writes(struct inode *inode) |
| 405 | { |
| 406 | fuse_set_nowrite(inode); |
| 407 | fuse_release_nowrite(inode); |
| 408 | } |
| 409 | |
| 410 | int fuse_fsync_common(struct file *file, loff_t start, loff_t end, |
| 411 | int datasync, int isdir) |
| 412 | { |
| 413 | struct inode *inode = file->f_mapping->host; |
| 414 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 415 | struct fuse_file *ff = file->private_data; |
| 416 | struct fuse_req *req; |
| 417 | struct fuse_fsync_in inarg; |
| 418 | int err; |
| 419 | |
| 420 | if (is_bad_inode(inode)) |
| 421 | return -EIO; |
| 422 | |
| 423 | err = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| 424 | if (err) |
| 425 | return err; |
| 426 | |
| 427 | if ((!isdir && fc->no_fsync) || (isdir && fc->no_fsyncdir)) |
| 428 | return 0; |
| 429 | |
| 430 | mutex_lock(&inode->i_mutex); |
| 431 | |
| 432 | /* |
| 433 | * Start writeback against all dirty pages of the inode, then |
| 434 | * wait for all outstanding writes, before sending the FSYNC |
| 435 | * request. |
| 436 | */ |
| 437 | err = write_inode_now(inode, 0); |
| 438 | if (err) |
| 439 | goto out; |
| 440 | |
| 441 | fuse_sync_writes(inode); |
| 442 | |
| 443 | req = fuse_get_req(fc); |
| 444 | if (IS_ERR(req)) { |
| 445 | err = PTR_ERR(req); |
| 446 | goto out; |
| 447 | } |
| 448 | |
| 449 | memset(&inarg, 0, sizeof(inarg)); |
| 450 | inarg.fh = ff->fh; |
| 451 | inarg.fsync_flags = datasync ? 1 : 0; |
| 452 | req->in.h.opcode = isdir ? FUSE_FSYNCDIR : FUSE_FSYNC; |
| 453 | req->in.h.nodeid = get_node_id(inode); |
| 454 | req->in.numargs = 1; |
| 455 | req->in.args[0].size = sizeof(inarg); |
| 456 | req->in.args[0].value = &inarg; |
| 457 | fuse_request_send(fc, req); |
| 458 | err = req->out.h.error; |
| 459 | fuse_put_request(fc, req); |
| 460 | if (err == -ENOSYS) { |
| 461 | if (isdir) |
| 462 | fc->no_fsyncdir = 1; |
| 463 | else |
| 464 | fc->no_fsync = 1; |
| 465 | err = 0; |
| 466 | } |
| 467 | out: |
| 468 | mutex_unlock(&inode->i_mutex); |
| 469 | return err; |
| 470 | } |
| 471 | |
| 472 | static int fuse_fsync(struct file *file, loff_t start, loff_t end, |
| 473 | int datasync) |
| 474 | { |
| 475 | return fuse_fsync_common(file, start, end, datasync, 0); |
| 476 | } |
| 477 | |
| 478 | void fuse_read_fill(struct fuse_req *req, struct file *file, loff_t pos, |
| 479 | size_t count, int opcode) |
| 480 | { |
| 481 | struct fuse_read_in *inarg = &req->misc.read.in; |
| 482 | struct fuse_file *ff = file->private_data; |
| 483 | |
| 484 | inarg->fh = ff->fh; |
| 485 | inarg->offset = pos; |
| 486 | inarg->size = count; |
| 487 | inarg->flags = file->f_flags; |
| 488 | req->in.h.opcode = opcode; |
| 489 | req->in.h.nodeid = ff->nodeid; |
| 490 | req->in.numargs = 1; |
| 491 | req->in.args[0].size = sizeof(struct fuse_read_in); |
| 492 | req->in.args[0].value = inarg; |
| 493 | req->out.argvar = 1; |
| 494 | req->out.numargs = 1; |
| 495 | req->out.args[0].size = count; |
| 496 | } |
| 497 | |
| 498 | static size_t fuse_send_read(struct fuse_req *req, struct file *file, |
| 499 | loff_t pos, size_t count, fl_owner_t owner) |
| 500 | { |
| 501 | struct fuse_file *ff = file->private_data; |
| 502 | struct fuse_conn *fc = ff->fc; |
| 503 | |
| 504 | fuse_read_fill(req, file, pos, count, FUSE_READ); |
| 505 | if (owner != NULL) { |
| 506 | struct fuse_read_in *inarg = &req->misc.read.in; |
| 507 | |
| 508 | inarg->read_flags |= FUSE_READ_LOCKOWNER; |
| 509 | inarg->lock_owner = fuse_lock_owner_id(fc, owner); |
| 510 | } |
| 511 | fuse_request_send(fc, req); |
| 512 | return req->out.args[0].size; |
| 513 | } |
| 514 | |
| 515 | static void fuse_read_update_size(struct inode *inode, loff_t size, |
| 516 | u64 attr_ver) |
| 517 | { |
| 518 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 519 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 520 | |
| 521 | spin_lock(&fc->lock); |
| 522 | if (attr_ver == fi->attr_version && size < inode->i_size) { |
| 523 | fi->attr_version = ++fc->attr_version; |
| 524 | i_size_write(inode, size); |
| 525 | } |
| 526 | spin_unlock(&fc->lock); |
| 527 | } |
| 528 | |
| 529 | static int fuse_readpage(struct file *file, struct page *page) |
| 530 | { |
| 531 | struct inode *inode = page->mapping->host; |
| 532 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 533 | struct fuse_req *req; |
| 534 | size_t num_read; |
| 535 | loff_t pos = page_offset(page); |
| 536 | size_t count = PAGE_CACHE_SIZE; |
| 537 | u64 attr_ver; |
| 538 | int err; |
| 539 | |
| 540 | err = -EIO; |
| 541 | if (is_bad_inode(inode)) |
| 542 | goto out; |
| 543 | |
| 544 | /* |
| 545 | * Page writeback can extend beyond the lifetime of the |
| 546 | * page-cache page, so make sure we read a properly synced |
| 547 | * page. |
| 548 | */ |
| 549 | fuse_wait_on_page_writeback(inode, page->index); |
| 550 | |
| 551 | req = fuse_get_req(fc); |
| 552 | err = PTR_ERR(req); |
| 553 | if (IS_ERR(req)) |
| 554 | goto out; |
| 555 | |
| 556 | attr_ver = fuse_get_attr_version(fc); |
| 557 | |
| 558 | req->out.page_zeroing = 1; |
| 559 | req->out.argpages = 1; |
| 560 | req->num_pages = 1; |
| 561 | req->pages[0] = page; |
| 562 | num_read = fuse_send_read(req, file, pos, count, NULL); |
| 563 | err = req->out.h.error; |
| 564 | fuse_put_request(fc, req); |
| 565 | |
| 566 | if (!err) { |
| 567 | /* |
| 568 | * Short read means EOF. If file size is larger, truncate it |
| 569 | */ |
| 570 | if (num_read < count) |
| 571 | fuse_read_update_size(inode, pos + num_read, attr_ver); |
| 572 | |
| 573 | SetPageUptodate(page); |
| 574 | } |
| 575 | |
| 576 | fuse_invalidate_attr(inode); /* atime changed */ |
| 577 | out: |
| 578 | unlock_page(page); |
| 579 | return err; |
| 580 | } |
| 581 | |
| 582 | static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req) |
| 583 | { |
| 584 | int i; |
| 585 | size_t count = req->misc.read.in.size; |
| 586 | size_t num_read = req->out.args[0].size; |
| 587 | struct address_space *mapping = NULL; |
| 588 | |
| 589 | for (i = 0; mapping == NULL && i < req->num_pages; i++) |
| 590 | mapping = req->pages[i]->mapping; |
| 591 | |
| 592 | if (mapping) { |
| 593 | struct inode *inode = mapping->host; |
| 594 | |
| 595 | /* |
| 596 | * Short read means EOF. If file size is larger, truncate it |
| 597 | */ |
| 598 | if (!req->out.h.error && num_read < count) { |
| 599 | loff_t pos; |
| 600 | |
| 601 | pos = page_offset(req->pages[0]) + num_read; |
| 602 | fuse_read_update_size(inode, pos, |
| 603 | req->misc.read.attr_ver); |
| 604 | } |
| 605 | fuse_invalidate_attr(inode); /* atime changed */ |
| 606 | } |
| 607 | |
| 608 | for (i = 0; i < req->num_pages; i++) { |
| 609 | struct page *page = req->pages[i]; |
| 610 | if (!req->out.h.error) |
| 611 | SetPageUptodate(page); |
| 612 | else |
| 613 | SetPageError(page); |
| 614 | unlock_page(page); |
| 615 | page_cache_release(page); |
| 616 | } |
| 617 | if (req->ff) |
| 618 | fuse_file_put(req->ff, false); |
| 619 | } |
| 620 | |
| 621 | static void fuse_send_readpages(struct fuse_req *req, struct file *file) |
| 622 | { |
| 623 | struct fuse_file *ff = file->private_data; |
| 624 | struct fuse_conn *fc = ff->fc; |
| 625 | loff_t pos = page_offset(req->pages[0]); |
| 626 | size_t count = req->num_pages << PAGE_CACHE_SHIFT; |
| 627 | |
| 628 | req->out.argpages = 1; |
| 629 | req->out.page_zeroing = 1; |
| 630 | req->out.page_replace = 1; |
| 631 | fuse_read_fill(req, file, pos, count, FUSE_READ); |
| 632 | req->misc.read.attr_ver = fuse_get_attr_version(fc); |
| 633 | if (fc->async_read) { |
| 634 | req->ff = fuse_file_get(ff); |
| 635 | req->end = fuse_readpages_end; |
| 636 | fuse_request_send_background(fc, req); |
| 637 | } else { |
| 638 | fuse_request_send(fc, req); |
| 639 | fuse_readpages_end(fc, req); |
| 640 | fuse_put_request(fc, req); |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | struct fuse_fill_data { |
| 645 | struct fuse_req *req; |
| 646 | struct file *file; |
| 647 | struct inode *inode; |
| 648 | }; |
| 649 | |
| 650 | static int fuse_readpages_fill(void *_data, struct page *page) |
| 651 | { |
| 652 | struct fuse_fill_data *data = _data; |
| 653 | struct fuse_req *req = data->req; |
| 654 | struct inode *inode = data->inode; |
| 655 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 656 | |
| 657 | fuse_wait_on_page_writeback(inode, page->index); |
| 658 | |
| 659 | if (req->num_pages && |
| 660 | (req->num_pages == FUSE_MAX_PAGES_PER_REQ || |
| 661 | (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read || |
| 662 | req->pages[req->num_pages - 1]->index + 1 != page->index)) { |
| 663 | fuse_send_readpages(req, data->file); |
| 664 | data->req = req = fuse_get_req(fc); |
| 665 | if (IS_ERR(req)) { |
| 666 | unlock_page(page); |
| 667 | return PTR_ERR(req); |
| 668 | } |
| 669 | } |
| 670 | page_cache_get(page); |
| 671 | req->pages[req->num_pages] = page; |
| 672 | req->num_pages++; |
| 673 | return 0; |
| 674 | } |
| 675 | |
| 676 | static int fuse_readpages(struct file *file, struct address_space *mapping, |
| 677 | struct list_head *pages, unsigned nr_pages) |
| 678 | { |
| 679 | struct inode *inode = mapping->host; |
| 680 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 681 | struct fuse_fill_data data; |
| 682 | int err; |
| 683 | |
| 684 | err = -EIO; |
| 685 | if (is_bad_inode(inode)) |
| 686 | goto out; |
| 687 | |
| 688 | data.file = file; |
| 689 | data.inode = inode; |
| 690 | data.req = fuse_get_req(fc); |
| 691 | err = PTR_ERR(data.req); |
| 692 | if (IS_ERR(data.req)) |
| 693 | goto out; |
| 694 | |
| 695 | err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data); |
| 696 | if (!err) { |
| 697 | if (data.req->num_pages) |
| 698 | fuse_send_readpages(data.req, file); |
| 699 | else |
| 700 | fuse_put_request(fc, data.req); |
| 701 | } |
| 702 | out: |
| 703 | return err; |
| 704 | } |
| 705 | |
| 706 | static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov, |
| 707 | unsigned long nr_segs, loff_t pos) |
| 708 | { |
| 709 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
| 710 | |
| 711 | if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) { |
| 712 | int err; |
| 713 | /* |
| 714 | * If trying to read past EOF, make sure the i_size |
| 715 | * attribute is up-to-date. |
| 716 | */ |
| 717 | err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL); |
| 718 | if (err) |
| 719 | return err; |
| 720 | } |
| 721 | |
| 722 | return generic_file_aio_read(iocb, iov, nr_segs, pos); |
| 723 | } |
| 724 | |
| 725 | static void fuse_write_fill(struct fuse_req *req, struct fuse_file *ff, |
| 726 | loff_t pos, size_t count) |
| 727 | { |
| 728 | struct fuse_write_in *inarg = &req->misc.write.in; |
| 729 | struct fuse_write_out *outarg = &req->misc.write.out; |
| 730 | |
| 731 | inarg->fh = ff->fh; |
| 732 | inarg->offset = pos; |
| 733 | inarg->size = count; |
| 734 | req->in.h.opcode = FUSE_WRITE; |
| 735 | req->in.h.nodeid = ff->nodeid; |
| 736 | req->in.numargs = 2; |
| 737 | if (ff->fc->minor < 9) |
| 738 | req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE; |
| 739 | else |
| 740 | req->in.args[0].size = sizeof(struct fuse_write_in); |
| 741 | req->in.args[0].value = inarg; |
| 742 | req->in.args[1].size = count; |
| 743 | req->out.numargs = 1; |
| 744 | req->out.args[0].size = sizeof(struct fuse_write_out); |
| 745 | req->out.args[0].value = outarg; |
| 746 | } |
| 747 | |
| 748 | static size_t fuse_send_write(struct fuse_req *req, struct file *file, |
| 749 | loff_t pos, size_t count, fl_owner_t owner) |
| 750 | { |
| 751 | struct fuse_file *ff = file->private_data; |
| 752 | struct fuse_conn *fc = ff->fc; |
| 753 | struct fuse_write_in *inarg = &req->misc.write.in; |
| 754 | |
| 755 | fuse_write_fill(req, ff, pos, count); |
| 756 | inarg->flags = file->f_flags; |
| 757 | if (owner != NULL) { |
| 758 | inarg->write_flags |= FUSE_WRITE_LOCKOWNER; |
| 759 | inarg->lock_owner = fuse_lock_owner_id(fc, owner); |
| 760 | } |
| 761 | fuse_request_send(fc, req); |
| 762 | return req->misc.write.out.size; |
| 763 | } |
| 764 | |
| 765 | void fuse_write_update_size(struct inode *inode, loff_t pos) |
| 766 | { |
| 767 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 768 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 769 | |
| 770 | spin_lock(&fc->lock); |
| 771 | fi->attr_version = ++fc->attr_version; |
| 772 | if (pos > inode->i_size) |
| 773 | i_size_write(inode, pos); |
| 774 | spin_unlock(&fc->lock); |
| 775 | } |
| 776 | |
| 777 | static size_t fuse_send_write_pages(struct fuse_req *req, struct file *file, |
| 778 | struct inode *inode, loff_t pos, |
| 779 | size_t count) |
| 780 | { |
| 781 | size_t res; |
| 782 | unsigned offset; |
| 783 | unsigned i; |
| 784 | |
| 785 | for (i = 0; i < req->num_pages; i++) |
| 786 | fuse_wait_on_page_writeback(inode, req->pages[i]->index); |
| 787 | |
| 788 | res = fuse_send_write(req, file, pos, count, NULL); |
| 789 | |
| 790 | offset = req->page_offset; |
| 791 | count = res; |
| 792 | for (i = 0; i < req->num_pages; i++) { |
| 793 | struct page *page = req->pages[i]; |
| 794 | |
| 795 | if (!req->out.h.error && !offset && count >= PAGE_CACHE_SIZE) |
| 796 | SetPageUptodate(page); |
| 797 | |
| 798 | if (count > PAGE_CACHE_SIZE - offset) |
| 799 | count -= PAGE_CACHE_SIZE - offset; |
| 800 | else |
| 801 | count = 0; |
| 802 | offset = 0; |
| 803 | |
| 804 | unlock_page(page); |
| 805 | page_cache_release(page); |
| 806 | } |
| 807 | |
| 808 | return res; |
| 809 | } |
| 810 | |
| 811 | static ssize_t fuse_fill_write_pages(struct fuse_req *req, |
| 812 | struct address_space *mapping, |
| 813 | struct iov_iter *ii, loff_t pos) |
| 814 | { |
| 815 | struct fuse_conn *fc = get_fuse_conn(mapping->host); |
| 816 | unsigned offset = pos & (PAGE_CACHE_SIZE - 1); |
| 817 | size_t count = 0; |
| 818 | int err; |
| 819 | |
| 820 | req->in.argpages = 1; |
| 821 | req->page_offset = offset; |
| 822 | |
| 823 | do { |
| 824 | size_t tmp; |
| 825 | struct page *page; |
| 826 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| 827 | size_t bytes = min_t(size_t, PAGE_CACHE_SIZE - offset, |
| 828 | iov_iter_count(ii)); |
| 829 | |
| 830 | bytes = min_t(size_t, bytes, fc->max_write - count); |
| 831 | |
| 832 | again: |
| 833 | err = -EFAULT; |
| 834 | if (iov_iter_fault_in_readable(ii, bytes)) |
| 835 | break; |
| 836 | |
| 837 | err = -ENOMEM; |
| 838 | page = grab_cache_page_write_begin(mapping, index, 0); |
| 839 | if (!page) |
| 840 | break; |
| 841 | |
| 842 | if (mapping_writably_mapped(mapping)) |
| 843 | flush_dcache_page(page); |
| 844 | |
| 845 | pagefault_disable(); |
| 846 | tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); |
| 847 | pagefault_enable(); |
| 848 | flush_dcache_page(page); |
| 849 | |
| 850 | mark_page_accessed(page); |
| 851 | |
| 852 | if (!tmp) { |
| 853 | unlock_page(page); |
| 854 | page_cache_release(page); |
| 855 | bytes = min(bytes, iov_iter_single_seg_count(ii)); |
| 856 | goto again; |
| 857 | } |
| 858 | |
| 859 | err = 0; |
| 860 | req->pages[req->num_pages] = page; |
| 861 | req->num_pages++; |
| 862 | |
| 863 | iov_iter_advance(ii, tmp); |
| 864 | count += tmp; |
| 865 | pos += tmp; |
| 866 | offset += tmp; |
| 867 | if (offset == PAGE_CACHE_SIZE) |
| 868 | offset = 0; |
| 869 | |
| 870 | if (!fc->big_writes) |
| 871 | break; |
| 872 | } while (iov_iter_count(ii) && count < fc->max_write && |
| 873 | req->num_pages < FUSE_MAX_PAGES_PER_REQ && offset == 0); |
| 874 | |
| 875 | return count > 0 ? count : err; |
| 876 | } |
| 877 | |
| 878 | static ssize_t fuse_perform_write(struct file *file, |
| 879 | struct address_space *mapping, |
| 880 | struct iov_iter *ii, loff_t pos) |
| 881 | { |
| 882 | struct inode *inode = mapping->host; |
| 883 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 884 | int err = 0; |
| 885 | ssize_t res = 0; |
| 886 | |
| 887 | if (is_bad_inode(inode)) |
| 888 | return -EIO; |
| 889 | |
| 890 | do { |
| 891 | struct fuse_req *req; |
| 892 | ssize_t count; |
| 893 | |
| 894 | req = fuse_get_req(fc); |
| 895 | if (IS_ERR(req)) { |
| 896 | err = PTR_ERR(req); |
| 897 | break; |
| 898 | } |
| 899 | |
| 900 | count = fuse_fill_write_pages(req, mapping, ii, pos); |
| 901 | if (count <= 0) { |
| 902 | err = count; |
| 903 | } else { |
| 904 | size_t num_written; |
| 905 | |
| 906 | num_written = fuse_send_write_pages(req, file, inode, |
| 907 | pos, count); |
| 908 | err = req->out.h.error; |
| 909 | if (!err) { |
| 910 | res += num_written; |
| 911 | pos += num_written; |
| 912 | |
| 913 | /* break out of the loop on short write */ |
| 914 | if (num_written != count) |
| 915 | err = -EIO; |
| 916 | } |
| 917 | } |
| 918 | fuse_put_request(fc, req); |
| 919 | } while (!err && iov_iter_count(ii)); |
| 920 | |
| 921 | if (res > 0) |
| 922 | fuse_write_update_size(inode, pos); |
| 923 | |
| 924 | fuse_invalidate_attr(inode); |
| 925 | |
| 926 | return res > 0 ? res : err; |
| 927 | } |
| 928 | |
| 929 | static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, |
| 930 | unsigned long nr_segs, loff_t pos) |
| 931 | { |
| 932 | struct file *file = iocb->ki_filp; |
| 933 | struct address_space *mapping = file->f_mapping; |
| 934 | size_t count = 0; |
| 935 | ssize_t written = 0; |
| 936 | struct inode *inode = mapping->host; |
| 937 | ssize_t err; |
| 938 | struct iov_iter i; |
| 939 | |
| 940 | WARN_ON(iocb->ki_pos != pos); |
| 941 | |
| 942 | err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ); |
| 943 | if (err) |
| 944 | return err; |
| 945 | |
| 946 | mutex_lock(&inode->i_mutex); |
| 947 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); |
| 948 | |
| 949 | /* We can write back this queue in page reclaim */ |
| 950 | current->backing_dev_info = mapping->backing_dev_info; |
| 951 | |
| 952 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
| 953 | if (err) |
| 954 | goto out; |
| 955 | |
| 956 | if (count == 0) |
| 957 | goto out; |
| 958 | |
| 959 | err = file_remove_suid(file); |
| 960 | if (err) |
| 961 | goto out; |
| 962 | |
| 963 | file_update_time(file); |
| 964 | |
| 965 | iov_iter_init(&i, iov, nr_segs, count, 0); |
| 966 | written = fuse_perform_write(file, mapping, &i, pos); |
| 967 | if (written >= 0) |
| 968 | iocb->ki_pos = pos + written; |
| 969 | |
| 970 | out: |
| 971 | current->backing_dev_info = NULL; |
| 972 | mutex_unlock(&inode->i_mutex); |
| 973 | |
| 974 | return written ? written : err; |
| 975 | } |
| 976 | |
| 977 | static void fuse_release_user_pages(struct fuse_req *req, int write) |
| 978 | { |
| 979 | unsigned i; |
| 980 | |
| 981 | for (i = 0; i < req->num_pages; i++) { |
| 982 | struct page *page = req->pages[i]; |
| 983 | if (write) |
| 984 | set_page_dirty_lock(page); |
| 985 | put_page(page); |
| 986 | } |
| 987 | } |
| 988 | |
| 989 | static int fuse_get_user_pages(struct fuse_req *req, const char __user *buf, |
| 990 | size_t *nbytesp, int write) |
| 991 | { |
| 992 | size_t nbytes = *nbytesp; |
| 993 | unsigned long user_addr = (unsigned long) buf; |
| 994 | unsigned offset = user_addr & ~PAGE_MASK; |
| 995 | int npages; |
| 996 | |
| 997 | /* Special case for kernel I/O: can copy directly into the buffer */ |
| 998 | if (segment_eq(get_fs(), KERNEL_DS)) { |
| 999 | if (write) |
| 1000 | req->in.args[1].value = (void *) user_addr; |
| 1001 | else |
| 1002 | req->out.args[0].value = (void *) user_addr; |
| 1003 | |
| 1004 | return 0; |
| 1005 | } |
| 1006 | |
| 1007 | nbytes = min_t(size_t, nbytes, FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT); |
| 1008 | npages = (nbytes + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1009 | npages = clamp(npages, 1, FUSE_MAX_PAGES_PER_REQ); |
| 1010 | npages = get_user_pages_fast(user_addr, npages, !write, req->pages); |
| 1011 | if (npages < 0) |
| 1012 | return npages; |
| 1013 | |
| 1014 | req->num_pages = npages; |
| 1015 | req->page_offset = offset; |
| 1016 | |
| 1017 | if (write) |
| 1018 | req->in.argpages = 1; |
| 1019 | else |
| 1020 | req->out.argpages = 1; |
| 1021 | |
| 1022 | nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset; |
| 1023 | *nbytesp = min(*nbytesp, nbytes); |
| 1024 | |
| 1025 | return 0; |
| 1026 | } |
| 1027 | |
| 1028 | ssize_t fuse_direct_io(struct file *file, const char __user *buf, |
| 1029 | size_t count, loff_t *ppos, int write) |
| 1030 | { |
| 1031 | struct fuse_file *ff = file->private_data; |
| 1032 | struct fuse_conn *fc = ff->fc; |
| 1033 | size_t nmax = write ? fc->max_write : fc->max_read; |
| 1034 | loff_t pos = *ppos; |
| 1035 | ssize_t res = 0; |
| 1036 | struct fuse_req *req; |
| 1037 | |
| 1038 | req = fuse_get_req(fc); |
| 1039 | if (IS_ERR(req)) |
| 1040 | return PTR_ERR(req); |
| 1041 | |
| 1042 | while (count) { |
| 1043 | size_t nres; |
| 1044 | fl_owner_t owner = current->files; |
| 1045 | size_t nbytes = min(count, nmax); |
| 1046 | int err = fuse_get_user_pages(req, buf, &nbytes, write); |
| 1047 | if (err) { |
| 1048 | res = err; |
| 1049 | break; |
| 1050 | } |
| 1051 | |
| 1052 | if (write) |
| 1053 | nres = fuse_send_write(req, file, pos, nbytes, owner); |
| 1054 | else |
| 1055 | nres = fuse_send_read(req, file, pos, nbytes, owner); |
| 1056 | |
| 1057 | fuse_release_user_pages(req, !write); |
| 1058 | if (req->out.h.error) { |
| 1059 | if (!res) |
| 1060 | res = req->out.h.error; |
| 1061 | break; |
| 1062 | } else if (nres > nbytes) { |
| 1063 | res = -EIO; |
| 1064 | break; |
| 1065 | } |
| 1066 | count -= nres; |
| 1067 | res += nres; |
| 1068 | pos += nres; |
| 1069 | buf += nres; |
| 1070 | if (nres != nbytes) |
| 1071 | break; |
| 1072 | if (count) { |
| 1073 | fuse_put_request(fc, req); |
| 1074 | req = fuse_get_req(fc); |
| 1075 | if (IS_ERR(req)) |
| 1076 | break; |
| 1077 | } |
| 1078 | } |
| 1079 | if (!IS_ERR(req)) |
| 1080 | fuse_put_request(fc, req); |
| 1081 | if (res > 0) |
| 1082 | *ppos = pos; |
| 1083 | |
| 1084 | return res; |
| 1085 | } |
| 1086 | EXPORT_SYMBOL_GPL(fuse_direct_io); |
| 1087 | |
| 1088 | static ssize_t fuse_direct_read(struct file *file, char __user *buf, |
| 1089 | size_t count, loff_t *ppos) |
| 1090 | { |
| 1091 | ssize_t res; |
| 1092 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1093 | |
| 1094 | if (is_bad_inode(inode)) |
| 1095 | return -EIO; |
| 1096 | |
| 1097 | res = fuse_direct_io(file, buf, count, ppos, 0); |
| 1098 | |
| 1099 | fuse_invalidate_attr(inode); |
| 1100 | |
| 1101 | return res; |
| 1102 | } |
| 1103 | |
| 1104 | static ssize_t fuse_direct_write(struct file *file, const char __user *buf, |
| 1105 | size_t count, loff_t *ppos) |
| 1106 | { |
| 1107 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1108 | ssize_t res; |
| 1109 | |
| 1110 | if (is_bad_inode(inode)) |
| 1111 | return -EIO; |
| 1112 | |
| 1113 | /* Don't allow parallel writes to the same file */ |
| 1114 | mutex_lock(&inode->i_mutex); |
| 1115 | res = generic_write_checks(file, ppos, &count, 0); |
| 1116 | if (!res) { |
| 1117 | res = fuse_direct_io(file, buf, count, ppos, 1); |
| 1118 | if (res > 0) |
| 1119 | fuse_write_update_size(inode, *ppos); |
| 1120 | } |
| 1121 | mutex_unlock(&inode->i_mutex); |
| 1122 | |
| 1123 | fuse_invalidate_attr(inode); |
| 1124 | |
| 1125 | return res; |
| 1126 | } |
| 1127 | |
| 1128 | static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req) |
| 1129 | { |
| 1130 | __free_page(req->pages[0]); |
| 1131 | fuse_file_put(req->ff, false); |
| 1132 | } |
| 1133 | |
| 1134 | static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req) |
| 1135 | { |
| 1136 | struct inode *inode = req->inode; |
| 1137 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 1138 | struct backing_dev_info *bdi = inode->i_mapping->backing_dev_info; |
| 1139 | |
| 1140 | list_del(&req->writepages_entry); |
| 1141 | dec_bdi_stat(bdi, BDI_WRITEBACK); |
| 1142 | dec_zone_page_state(req->pages[0], NR_WRITEBACK_TEMP); |
| 1143 | bdi_writeout_inc(bdi); |
| 1144 | wake_up(&fi->page_waitq); |
| 1145 | } |
| 1146 | |
| 1147 | /* Called under fc->lock, may release and reacquire it */ |
| 1148 | static void fuse_send_writepage(struct fuse_conn *fc, struct fuse_req *req) |
| 1149 | __releases(fc->lock) |
| 1150 | __acquires(fc->lock) |
| 1151 | { |
| 1152 | struct fuse_inode *fi = get_fuse_inode(req->inode); |
| 1153 | loff_t size = i_size_read(req->inode); |
| 1154 | struct fuse_write_in *inarg = &req->misc.write.in; |
| 1155 | |
| 1156 | if (!fc->connected) |
| 1157 | goto out_free; |
| 1158 | |
| 1159 | if (inarg->offset + PAGE_CACHE_SIZE <= size) { |
| 1160 | inarg->size = PAGE_CACHE_SIZE; |
| 1161 | } else if (inarg->offset < size) { |
| 1162 | inarg->size = size & (PAGE_CACHE_SIZE - 1); |
| 1163 | } else { |
| 1164 | /* Got truncated off completely */ |
| 1165 | goto out_free; |
| 1166 | } |
| 1167 | |
| 1168 | req->in.args[1].size = inarg->size; |
| 1169 | fi->writectr++; |
| 1170 | fuse_request_send_background_locked(fc, req); |
| 1171 | return; |
| 1172 | |
| 1173 | out_free: |
| 1174 | fuse_writepage_finish(fc, req); |
| 1175 | spin_unlock(&fc->lock); |
| 1176 | fuse_writepage_free(fc, req); |
| 1177 | fuse_put_request(fc, req); |
| 1178 | spin_lock(&fc->lock); |
| 1179 | } |
| 1180 | |
| 1181 | /* |
| 1182 | * If fi->writectr is positive (no truncate or fsync going on) send |
| 1183 | * all queued writepage requests. |
| 1184 | * |
| 1185 | * Called with fc->lock |
| 1186 | */ |
| 1187 | void fuse_flush_writepages(struct inode *inode) |
| 1188 | __releases(fc->lock) |
| 1189 | __acquires(fc->lock) |
| 1190 | { |
| 1191 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1192 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 1193 | struct fuse_req *req; |
| 1194 | |
| 1195 | while (fi->writectr >= 0 && !list_empty(&fi->queued_writes)) { |
| 1196 | req = list_entry(fi->queued_writes.next, struct fuse_req, list); |
| 1197 | list_del_init(&req->list); |
| 1198 | fuse_send_writepage(fc, req); |
| 1199 | } |
| 1200 | } |
| 1201 | |
| 1202 | static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req) |
| 1203 | { |
| 1204 | struct inode *inode = req->inode; |
| 1205 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 1206 | |
| 1207 | mapping_set_error(inode->i_mapping, req->out.h.error); |
| 1208 | spin_lock(&fc->lock); |
| 1209 | fi->writectr--; |
| 1210 | fuse_writepage_finish(fc, req); |
| 1211 | spin_unlock(&fc->lock); |
| 1212 | fuse_writepage_free(fc, req); |
| 1213 | } |
| 1214 | |
| 1215 | static int fuse_writepage_locked(struct page *page) |
| 1216 | { |
| 1217 | struct address_space *mapping = page->mapping; |
| 1218 | struct inode *inode = mapping->host; |
| 1219 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1220 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 1221 | struct fuse_req *req; |
| 1222 | struct fuse_file *ff; |
| 1223 | struct page *tmp_page; |
| 1224 | |
| 1225 | set_page_writeback(page); |
| 1226 | |
| 1227 | req = fuse_request_alloc_nofs(); |
| 1228 | if (!req) |
| 1229 | goto err; |
| 1230 | |
| 1231 | tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); |
| 1232 | if (!tmp_page) |
| 1233 | goto err_free; |
| 1234 | |
| 1235 | spin_lock(&fc->lock); |
| 1236 | BUG_ON(list_empty(&fi->write_files)); |
| 1237 | ff = list_entry(fi->write_files.next, struct fuse_file, write_entry); |
| 1238 | req->ff = fuse_file_get(ff); |
| 1239 | spin_unlock(&fc->lock); |
| 1240 | |
| 1241 | fuse_write_fill(req, ff, page_offset(page), 0); |
| 1242 | |
| 1243 | copy_highpage(tmp_page, page); |
| 1244 | req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; |
| 1245 | req->in.argpages = 1; |
| 1246 | req->num_pages = 1; |
| 1247 | req->pages[0] = tmp_page; |
| 1248 | req->page_offset = 0; |
| 1249 | req->end = fuse_writepage_end; |
| 1250 | req->inode = inode; |
| 1251 | |
| 1252 | inc_bdi_stat(mapping->backing_dev_info, BDI_WRITEBACK); |
| 1253 | inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP); |
| 1254 | end_page_writeback(page); |
| 1255 | |
| 1256 | spin_lock(&fc->lock); |
| 1257 | list_add(&req->writepages_entry, &fi->writepages); |
| 1258 | list_add_tail(&req->list, &fi->queued_writes); |
| 1259 | fuse_flush_writepages(inode); |
| 1260 | spin_unlock(&fc->lock); |
| 1261 | |
| 1262 | return 0; |
| 1263 | |
| 1264 | err_free: |
| 1265 | fuse_request_free(req); |
| 1266 | err: |
| 1267 | end_page_writeback(page); |
| 1268 | return -ENOMEM; |
| 1269 | } |
| 1270 | |
| 1271 | static int fuse_writepage(struct page *page, struct writeback_control *wbc) |
| 1272 | { |
| 1273 | int err; |
| 1274 | |
| 1275 | err = fuse_writepage_locked(page); |
| 1276 | unlock_page(page); |
| 1277 | |
| 1278 | return err; |
| 1279 | } |
| 1280 | |
| 1281 | static int fuse_launder_page(struct page *page) |
| 1282 | { |
| 1283 | int err = 0; |
| 1284 | if (clear_page_dirty_for_io(page)) { |
| 1285 | struct inode *inode = page->mapping->host; |
| 1286 | err = fuse_writepage_locked(page); |
| 1287 | if (!err) |
| 1288 | fuse_wait_on_page_writeback(inode, page->index); |
| 1289 | } |
| 1290 | return err; |
| 1291 | } |
| 1292 | |
| 1293 | /* |
| 1294 | * Write back dirty pages now, because there may not be any suitable |
| 1295 | * open files later |
| 1296 | */ |
| 1297 | static void fuse_vma_close(struct vm_area_struct *vma) |
| 1298 | { |
| 1299 | filemap_write_and_wait(vma->vm_file->f_mapping); |
| 1300 | } |
| 1301 | |
| 1302 | /* |
| 1303 | * Wait for writeback against this page to complete before allowing it |
| 1304 | * to be marked dirty again, and hence written back again, possibly |
| 1305 | * before the previous writepage completed. |
| 1306 | * |
| 1307 | * Block here, instead of in ->writepage(), so that the userspace fs |
| 1308 | * can only block processes actually operating on the filesystem. |
| 1309 | * |
| 1310 | * Otherwise unprivileged userspace fs would be able to block |
| 1311 | * unrelated: |
| 1312 | * |
| 1313 | * - page migration |
| 1314 | * - sync(2) |
| 1315 | * - try_to_free_pages() with order > PAGE_ALLOC_COSTLY_ORDER |
| 1316 | */ |
| 1317 | static int fuse_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 1318 | { |
| 1319 | struct page *page = vmf->page; |
| 1320 | /* |
| 1321 | * Don't use page->mapping as it may become NULL from a |
| 1322 | * concurrent truncate. |
| 1323 | */ |
| 1324 | struct inode *inode = vma->vm_file->f_mapping->host; |
| 1325 | |
| 1326 | fuse_wait_on_page_writeback(inode, page->index); |
| 1327 | return 0; |
| 1328 | } |
| 1329 | |
| 1330 | static const struct vm_operations_struct fuse_file_vm_ops = { |
| 1331 | .close = fuse_vma_close, |
| 1332 | .fault = filemap_fault, |
| 1333 | .page_mkwrite = fuse_page_mkwrite, |
| 1334 | }; |
| 1335 | |
| 1336 | static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) |
| 1337 | { |
| 1338 | if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) { |
| 1339 | struct inode *inode = file->f_dentry->d_inode; |
| 1340 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1341 | struct fuse_inode *fi = get_fuse_inode(inode); |
| 1342 | struct fuse_file *ff = file->private_data; |
| 1343 | /* |
| 1344 | * file may be written through mmap, so chain it onto the |
| 1345 | * inodes's write_file list |
| 1346 | */ |
| 1347 | spin_lock(&fc->lock); |
| 1348 | if (list_empty(&ff->write_entry)) |
| 1349 | list_add(&ff->write_entry, &fi->write_files); |
| 1350 | spin_unlock(&fc->lock); |
| 1351 | } |
| 1352 | file_accessed(file); |
| 1353 | vma->vm_ops = &fuse_file_vm_ops; |
| 1354 | return 0; |
| 1355 | } |
| 1356 | |
| 1357 | static int fuse_direct_mmap(struct file *file, struct vm_area_struct *vma) |
| 1358 | { |
| 1359 | /* Can't provide the coherency needed for MAP_SHARED */ |
| 1360 | if (vma->vm_flags & VM_MAYSHARE) |
| 1361 | return -ENODEV; |
| 1362 | |
| 1363 | invalidate_inode_pages2(file->f_mapping); |
| 1364 | |
| 1365 | return generic_file_mmap(file, vma); |
| 1366 | } |
| 1367 | |
| 1368 | static int convert_fuse_file_lock(const struct fuse_file_lock *ffl, |
| 1369 | struct file_lock *fl) |
| 1370 | { |
| 1371 | switch (ffl->type) { |
| 1372 | case F_UNLCK: |
| 1373 | break; |
| 1374 | |
| 1375 | case F_RDLCK: |
| 1376 | case F_WRLCK: |
| 1377 | if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX || |
| 1378 | ffl->end < ffl->start) |
| 1379 | return -EIO; |
| 1380 | |
| 1381 | fl->fl_start = ffl->start; |
| 1382 | fl->fl_end = ffl->end; |
| 1383 | fl->fl_pid = ffl->pid; |
| 1384 | break; |
| 1385 | |
| 1386 | default: |
| 1387 | return -EIO; |
| 1388 | } |
| 1389 | fl->fl_type = ffl->type; |
| 1390 | return 0; |
| 1391 | } |
| 1392 | |
| 1393 | static void fuse_lk_fill(struct fuse_req *req, struct file *file, |
| 1394 | const struct file_lock *fl, int opcode, pid_t pid, |
| 1395 | int flock) |
| 1396 | { |
| 1397 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1398 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1399 | struct fuse_file *ff = file->private_data; |
| 1400 | struct fuse_lk_in *arg = &req->misc.lk_in; |
| 1401 | |
| 1402 | arg->fh = ff->fh; |
| 1403 | arg->owner = fuse_lock_owner_id(fc, fl->fl_owner); |
| 1404 | arg->lk.start = fl->fl_start; |
| 1405 | arg->lk.end = fl->fl_end; |
| 1406 | arg->lk.type = fl->fl_type; |
| 1407 | arg->lk.pid = pid; |
| 1408 | if (flock) |
| 1409 | arg->lk_flags |= FUSE_LK_FLOCK; |
| 1410 | req->in.h.opcode = opcode; |
| 1411 | req->in.h.nodeid = get_node_id(inode); |
| 1412 | req->in.numargs = 1; |
| 1413 | req->in.args[0].size = sizeof(*arg); |
| 1414 | req->in.args[0].value = arg; |
| 1415 | } |
| 1416 | |
| 1417 | static int fuse_getlk(struct file *file, struct file_lock *fl) |
| 1418 | { |
| 1419 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1420 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1421 | struct fuse_req *req; |
| 1422 | struct fuse_lk_out outarg; |
| 1423 | int err; |
| 1424 | |
| 1425 | req = fuse_get_req(fc); |
| 1426 | if (IS_ERR(req)) |
| 1427 | return PTR_ERR(req); |
| 1428 | |
| 1429 | fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0); |
| 1430 | req->out.numargs = 1; |
| 1431 | req->out.args[0].size = sizeof(outarg); |
| 1432 | req->out.args[0].value = &outarg; |
| 1433 | fuse_request_send(fc, req); |
| 1434 | err = req->out.h.error; |
| 1435 | fuse_put_request(fc, req); |
| 1436 | if (!err) |
| 1437 | err = convert_fuse_file_lock(&outarg.lk, fl); |
| 1438 | |
| 1439 | return err; |
| 1440 | } |
| 1441 | |
| 1442 | static int fuse_setlk(struct file *file, struct file_lock *fl, int flock) |
| 1443 | { |
| 1444 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1445 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1446 | struct fuse_req *req; |
| 1447 | int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK; |
| 1448 | pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0; |
| 1449 | int err; |
| 1450 | |
| 1451 | if (fl->fl_lmops && fl->fl_lmops->lm_grant) { |
| 1452 | /* NLM needs asynchronous locks, which we don't support yet */ |
| 1453 | return -ENOLCK; |
| 1454 | } |
| 1455 | |
| 1456 | /* Unlock on close is handled by the flush method */ |
| 1457 | if (fl->fl_flags & FL_CLOSE) |
| 1458 | return 0; |
| 1459 | |
| 1460 | req = fuse_get_req(fc); |
| 1461 | if (IS_ERR(req)) |
| 1462 | return PTR_ERR(req); |
| 1463 | |
| 1464 | fuse_lk_fill(req, file, fl, opcode, pid, flock); |
| 1465 | fuse_request_send(fc, req); |
| 1466 | err = req->out.h.error; |
| 1467 | /* locking is restartable */ |
| 1468 | if (err == -EINTR) |
| 1469 | err = -ERESTARTSYS; |
| 1470 | fuse_put_request(fc, req); |
| 1471 | return err; |
| 1472 | } |
| 1473 | |
| 1474 | static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl) |
| 1475 | { |
| 1476 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1477 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1478 | int err; |
| 1479 | |
| 1480 | if (cmd == F_CANCELLK) { |
| 1481 | err = 0; |
| 1482 | } else if (cmd == F_GETLK) { |
| 1483 | if (fc->no_lock) { |
| 1484 | posix_test_lock(file, fl); |
| 1485 | err = 0; |
| 1486 | } else |
| 1487 | err = fuse_getlk(file, fl); |
| 1488 | } else { |
| 1489 | if (fc->no_lock) |
| 1490 | err = posix_lock_file(file, fl, NULL); |
| 1491 | else |
| 1492 | err = fuse_setlk(file, fl, 0); |
| 1493 | } |
| 1494 | return err; |
| 1495 | } |
| 1496 | |
| 1497 | static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl) |
| 1498 | { |
| 1499 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1500 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1501 | int err; |
| 1502 | |
| 1503 | if (fc->no_flock) { |
| 1504 | err = flock_lock_file_wait(file, fl); |
| 1505 | } else { |
| 1506 | struct fuse_file *ff = file->private_data; |
| 1507 | |
| 1508 | /* emulate flock with POSIX locks */ |
| 1509 | fl->fl_owner = (fl_owner_t) file; |
| 1510 | ff->flock = true; |
| 1511 | err = fuse_setlk(file, fl, 1); |
| 1512 | } |
| 1513 | |
| 1514 | return err; |
| 1515 | } |
| 1516 | |
| 1517 | static sector_t fuse_bmap(struct address_space *mapping, sector_t block) |
| 1518 | { |
| 1519 | struct inode *inode = mapping->host; |
| 1520 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1521 | struct fuse_req *req; |
| 1522 | struct fuse_bmap_in inarg; |
| 1523 | struct fuse_bmap_out outarg; |
| 1524 | int err; |
| 1525 | |
| 1526 | if (!inode->i_sb->s_bdev || fc->no_bmap) |
| 1527 | return 0; |
| 1528 | |
| 1529 | req = fuse_get_req(fc); |
| 1530 | if (IS_ERR(req)) |
| 1531 | return 0; |
| 1532 | |
| 1533 | memset(&inarg, 0, sizeof(inarg)); |
| 1534 | inarg.block = block; |
| 1535 | inarg.blocksize = inode->i_sb->s_blocksize; |
| 1536 | req->in.h.opcode = FUSE_BMAP; |
| 1537 | req->in.h.nodeid = get_node_id(inode); |
| 1538 | req->in.numargs = 1; |
| 1539 | req->in.args[0].size = sizeof(inarg); |
| 1540 | req->in.args[0].value = &inarg; |
| 1541 | req->out.numargs = 1; |
| 1542 | req->out.args[0].size = sizeof(outarg); |
| 1543 | req->out.args[0].value = &outarg; |
| 1544 | fuse_request_send(fc, req); |
| 1545 | err = req->out.h.error; |
| 1546 | fuse_put_request(fc, req); |
| 1547 | if (err == -ENOSYS) |
| 1548 | fc->no_bmap = 1; |
| 1549 | |
| 1550 | return err ? 0 : outarg.block; |
| 1551 | } |
| 1552 | |
| 1553 | static loff_t fuse_file_llseek(struct file *file, loff_t offset, int origin) |
| 1554 | { |
| 1555 | loff_t retval; |
| 1556 | struct inode *inode = file->f_path.dentry->d_inode; |
| 1557 | |
| 1558 | /* No i_mutex protection necessary for SEEK_CUR and SEEK_SET */ |
| 1559 | if (origin == SEEK_CUR || origin == SEEK_SET) |
| 1560 | return generic_file_llseek(file, offset, origin); |
| 1561 | |
| 1562 | mutex_lock(&inode->i_mutex); |
| 1563 | retval = fuse_update_attributes(inode, NULL, file, NULL); |
| 1564 | if (!retval) |
| 1565 | retval = generic_file_llseek(file, offset, origin); |
| 1566 | mutex_unlock(&inode->i_mutex); |
| 1567 | |
| 1568 | return retval; |
| 1569 | } |
| 1570 | |
| 1571 | static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov, |
| 1572 | unsigned int nr_segs, size_t bytes, bool to_user) |
| 1573 | { |
| 1574 | struct iov_iter ii; |
| 1575 | int page_idx = 0; |
| 1576 | |
| 1577 | if (!bytes) |
| 1578 | return 0; |
| 1579 | |
| 1580 | iov_iter_init(&ii, iov, nr_segs, bytes, 0); |
| 1581 | |
| 1582 | while (iov_iter_count(&ii)) { |
| 1583 | struct page *page = pages[page_idx++]; |
| 1584 | size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii)); |
| 1585 | void *kaddr; |
| 1586 | |
| 1587 | kaddr = kmap(page); |
| 1588 | |
| 1589 | while (todo) { |
| 1590 | char __user *uaddr = ii.iov->iov_base + ii.iov_offset; |
| 1591 | size_t iov_len = ii.iov->iov_len - ii.iov_offset; |
| 1592 | size_t copy = min(todo, iov_len); |
| 1593 | size_t left; |
| 1594 | |
| 1595 | if (!to_user) |
| 1596 | left = copy_from_user(kaddr, uaddr, copy); |
| 1597 | else |
| 1598 | left = copy_to_user(uaddr, kaddr, copy); |
| 1599 | |
| 1600 | if (unlikely(left)) |
| 1601 | return -EFAULT; |
| 1602 | |
| 1603 | iov_iter_advance(&ii, copy); |
| 1604 | todo -= copy; |
| 1605 | kaddr += copy; |
| 1606 | } |
| 1607 | |
| 1608 | kunmap(page); |
| 1609 | } |
| 1610 | |
| 1611 | return 0; |
| 1612 | } |
| 1613 | |
| 1614 | /* |
| 1615 | * CUSE servers compiled on 32bit broke on 64bit kernels because the |
| 1616 | * ABI was defined to be 'struct iovec' which is different on 32bit |
| 1617 | * and 64bit. Fortunately we can determine which structure the server |
| 1618 | * used from the size of the reply. |
| 1619 | */ |
| 1620 | static int fuse_copy_ioctl_iovec_old(struct iovec *dst, void *src, |
| 1621 | size_t transferred, unsigned count, |
| 1622 | bool is_compat) |
| 1623 | { |
| 1624 | #ifdef CONFIG_COMPAT |
| 1625 | if (count * sizeof(struct compat_iovec) == transferred) { |
| 1626 | struct compat_iovec *ciov = src; |
| 1627 | unsigned i; |
| 1628 | |
| 1629 | /* |
| 1630 | * With this interface a 32bit server cannot support |
| 1631 | * non-compat (i.e. ones coming from 64bit apps) ioctl |
| 1632 | * requests |
| 1633 | */ |
| 1634 | if (!is_compat) |
| 1635 | return -EINVAL; |
| 1636 | |
| 1637 | for (i = 0; i < count; i++) { |
| 1638 | dst[i].iov_base = compat_ptr(ciov[i].iov_base); |
| 1639 | dst[i].iov_len = ciov[i].iov_len; |
| 1640 | } |
| 1641 | return 0; |
| 1642 | } |
| 1643 | #endif |
| 1644 | |
| 1645 | if (count * sizeof(struct iovec) != transferred) |
| 1646 | return -EIO; |
| 1647 | |
| 1648 | memcpy(dst, src, transferred); |
| 1649 | return 0; |
| 1650 | } |
| 1651 | |
| 1652 | /* Make sure iov_length() won't overflow */ |
| 1653 | static int fuse_verify_ioctl_iov(struct iovec *iov, size_t count) |
| 1654 | { |
| 1655 | size_t n; |
| 1656 | u32 max = FUSE_MAX_PAGES_PER_REQ << PAGE_SHIFT; |
| 1657 | |
| 1658 | for (n = 0; n < count; n++) { |
| 1659 | if (iov->iov_len > (size_t) max) |
| 1660 | return -ENOMEM; |
| 1661 | max -= iov->iov_len; |
| 1662 | } |
| 1663 | return 0; |
| 1664 | } |
| 1665 | |
| 1666 | static int fuse_copy_ioctl_iovec(struct fuse_conn *fc, struct iovec *dst, |
| 1667 | void *src, size_t transferred, unsigned count, |
| 1668 | bool is_compat) |
| 1669 | { |
| 1670 | unsigned i; |
| 1671 | struct fuse_ioctl_iovec *fiov = src; |
| 1672 | |
| 1673 | if (fc->minor < 16) { |
| 1674 | return fuse_copy_ioctl_iovec_old(dst, src, transferred, |
| 1675 | count, is_compat); |
| 1676 | } |
| 1677 | |
| 1678 | if (count * sizeof(struct fuse_ioctl_iovec) != transferred) |
| 1679 | return -EIO; |
| 1680 | |
| 1681 | for (i = 0; i < count; i++) { |
| 1682 | /* Did the server supply an inappropriate value? */ |
| 1683 | if (fiov[i].base != (unsigned long) fiov[i].base || |
| 1684 | fiov[i].len != (unsigned long) fiov[i].len) |
| 1685 | return -EIO; |
| 1686 | |
| 1687 | dst[i].iov_base = (void __user *) (unsigned long) fiov[i].base; |
| 1688 | dst[i].iov_len = (size_t) fiov[i].len; |
| 1689 | |
| 1690 | #ifdef CONFIG_COMPAT |
| 1691 | if (is_compat && |
| 1692 | (ptr_to_compat(dst[i].iov_base) != fiov[i].base || |
| 1693 | (compat_size_t) dst[i].iov_len != fiov[i].len)) |
| 1694 | return -EIO; |
| 1695 | #endif |
| 1696 | } |
| 1697 | |
| 1698 | return 0; |
| 1699 | } |
| 1700 | |
| 1701 | |
| 1702 | /* |
| 1703 | * For ioctls, there is no generic way to determine how much memory |
| 1704 | * needs to be read and/or written. Furthermore, ioctls are allowed |
| 1705 | * to dereference the passed pointer, so the parameter requires deep |
| 1706 | * copying but FUSE has no idea whatsoever about what to copy in or |
| 1707 | * out. |
| 1708 | * |
| 1709 | * This is solved by allowing FUSE server to retry ioctl with |
| 1710 | * necessary in/out iovecs. Let's assume the ioctl implementation |
| 1711 | * needs to read in the following structure. |
| 1712 | * |
| 1713 | * struct a { |
| 1714 | * char *buf; |
| 1715 | * size_t buflen; |
| 1716 | * } |
| 1717 | * |
| 1718 | * On the first callout to FUSE server, inarg->in_size and |
| 1719 | * inarg->out_size will be NULL; then, the server completes the ioctl |
| 1720 | * with FUSE_IOCTL_RETRY set in out->flags, out->in_iovs set to 1 and |
| 1721 | * the actual iov array to |
| 1722 | * |
| 1723 | * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) } } |
| 1724 | * |
| 1725 | * which tells FUSE to copy in the requested area and retry the ioctl. |
| 1726 | * On the second round, the server has access to the structure and |
| 1727 | * from that it can tell what to look for next, so on the invocation, |
| 1728 | * it sets FUSE_IOCTL_RETRY, out->in_iovs to 2 and iov array to |
| 1729 | * |
| 1730 | * { { .iov_base = inarg.arg, .iov_len = sizeof(struct a) }, |
| 1731 | * { .iov_base = a.buf, .iov_len = a.buflen } } |
| 1732 | * |
| 1733 | * FUSE will copy both struct a and the pointed buffer from the |
| 1734 | * process doing the ioctl and retry ioctl with both struct a and the |
| 1735 | * buffer. |
| 1736 | * |
| 1737 | * This time, FUSE server has everything it needs and completes ioctl |
| 1738 | * without FUSE_IOCTL_RETRY which finishes the ioctl call. |
| 1739 | * |
| 1740 | * Copying data out works the same way. |
| 1741 | * |
| 1742 | * Note that if FUSE_IOCTL_UNRESTRICTED is clear, the kernel |
| 1743 | * automatically initializes in and out iovs by decoding @cmd with |
| 1744 | * _IOC_* macros and the server is not allowed to request RETRY. This |
| 1745 | * limits ioctl data transfers to well-formed ioctls and is the forced |
| 1746 | * behavior for all FUSE servers. |
| 1747 | */ |
| 1748 | long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, |
| 1749 | unsigned int flags) |
| 1750 | { |
| 1751 | struct fuse_file *ff = file->private_data; |
| 1752 | struct fuse_conn *fc = ff->fc; |
| 1753 | struct fuse_ioctl_in inarg = { |
| 1754 | .fh = ff->fh, |
| 1755 | .cmd = cmd, |
| 1756 | .arg = arg, |
| 1757 | .flags = flags |
| 1758 | }; |
| 1759 | struct fuse_ioctl_out outarg; |
| 1760 | struct fuse_req *req = NULL; |
| 1761 | struct page **pages = NULL; |
| 1762 | struct iovec *iov_page = NULL; |
| 1763 | struct iovec *in_iov = NULL, *out_iov = NULL; |
| 1764 | unsigned int in_iovs = 0, out_iovs = 0, num_pages = 0, max_pages; |
| 1765 | size_t in_size, out_size, transferred; |
| 1766 | int err; |
| 1767 | |
| 1768 | #if BITS_PER_LONG == 32 |
| 1769 | inarg.flags |= FUSE_IOCTL_32BIT; |
| 1770 | #else |
| 1771 | if (flags & FUSE_IOCTL_COMPAT) |
| 1772 | inarg.flags |= FUSE_IOCTL_32BIT; |
| 1773 | #endif |
| 1774 | |
| 1775 | /* assume all the iovs returned by client always fits in a page */ |
| 1776 | BUILD_BUG_ON(sizeof(struct fuse_ioctl_iovec) * FUSE_IOCTL_MAX_IOV > PAGE_SIZE); |
| 1777 | |
| 1778 | err = -ENOMEM; |
| 1779 | pages = kcalloc(FUSE_MAX_PAGES_PER_REQ, sizeof(pages[0]), GFP_KERNEL); |
| 1780 | iov_page = (struct iovec *) __get_free_page(GFP_KERNEL); |
| 1781 | if (!pages || !iov_page) |
| 1782 | goto out; |
| 1783 | |
| 1784 | /* |
| 1785 | * If restricted, initialize IO parameters as encoded in @cmd. |
| 1786 | * RETRY from server is not allowed. |
| 1787 | */ |
| 1788 | if (!(flags & FUSE_IOCTL_UNRESTRICTED)) { |
| 1789 | struct iovec *iov = iov_page; |
| 1790 | |
| 1791 | iov->iov_base = (void __user *)arg; |
| 1792 | iov->iov_len = _IOC_SIZE(cmd); |
| 1793 | |
| 1794 | if (_IOC_DIR(cmd) & _IOC_WRITE) { |
| 1795 | in_iov = iov; |
| 1796 | in_iovs = 1; |
| 1797 | } |
| 1798 | |
| 1799 | if (_IOC_DIR(cmd) & _IOC_READ) { |
| 1800 | out_iov = iov; |
| 1801 | out_iovs = 1; |
| 1802 | } |
| 1803 | } |
| 1804 | |
| 1805 | retry: |
| 1806 | inarg.in_size = in_size = iov_length(in_iov, in_iovs); |
| 1807 | inarg.out_size = out_size = iov_length(out_iov, out_iovs); |
| 1808 | |
| 1809 | /* |
| 1810 | * Out data can be used either for actual out data or iovs, |
| 1811 | * make sure there always is at least one page. |
| 1812 | */ |
| 1813 | out_size = max_t(size_t, out_size, PAGE_SIZE); |
| 1814 | max_pages = DIV_ROUND_UP(max(in_size, out_size), PAGE_SIZE); |
| 1815 | |
| 1816 | /* make sure there are enough buffer pages and init request with them */ |
| 1817 | err = -ENOMEM; |
| 1818 | if (max_pages > FUSE_MAX_PAGES_PER_REQ) |
| 1819 | goto out; |
| 1820 | while (num_pages < max_pages) { |
| 1821 | pages[num_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); |
| 1822 | if (!pages[num_pages]) |
| 1823 | goto out; |
| 1824 | num_pages++; |
| 1825 | } |
| 1826 | |
| 1827 | req = fuse_get_req(fc); |
| 1828 | if (IS_ERR(req)) { |
| 1829 | err = PTR_ERR(req); |
| 1830 | req = NULL; |
| 1831 | goto out; |
| 1832 | } |
| 1833 | memcpy(req->pages, pages, sizeof(req->pages[0]) * num_pages); |
| 1834 | req->num_pages = num_pages; |
| 1835 | |
| 1836 | /* okay, let's send it to the client */ |
| 1837 | req->in.h.opcode = FUSE_IOCTL; |
| 1838 | req->in.h.nodeid = ff->nodeid; |
| 1839 | req->in.numargs = 1; |
| 1840 | req->in.args[0].size = sizeof(inarg); |
| 1841 | req->in.args[0].value = &inarg; |
| 1842 | if (in_size) { |
| 1843 | req->in.numargs++; |
| 1844 | req->in.args[1].size = in_size; |
| 1845 | req->in.argpages = 1; |
| 1846 | |
| 1847 | err = fuse_ioctl_copy_user(pages, in_iov, in_iovs, in_size, |
| 1848 | false); |
| 1849 | if (err) |
| 1850 | goto out; |
| 1851 | } |
| 1852 | |
| 1853 | req->out.numargs = 2; |
| 1854 | req->out.args[0].size = sizeof(outarg); |
| 1855 | req->out.args[0].value = &outarg; |
| 1856 | req->out.args[1].size = out_size; |
| 1857 | req->out.argpages = 1; |
| 1858 | req->out.argvar = 1; |
| 1859 | |
| 1860 | fuse_request_send(fc, req); |
| 1861 | err = req->out.h.error; |
| 1862 | transferred = req->out.args[1].size; |
| 1863 | fuse_put_request(fc, req); |
| 1864 | req = NULL; |
| 1865 | if (err) |
| 1866 | goto out; |
| 1867 | |
| 1868 | /* did it ask for retry? */ |
| 1869 | if (outarg.flags & FUSE_IOCTL_RETRY) { |
| 1870 | void *vaddr; |
| 1871 | |
| 1872 | /* no retry if in restricted mode */ |
| 1873 | err = -EIO; |
| 1874 | if (!(flags & FUSE_IOCTL_UNRESTRICTED)) |
| 1875 | goto out; |
| 1876 | |
| 1877 | in_iovs = outarg.in_iovs; |
| 1878 | out_iovs = outarg.out_iovs; |
| 1879 | |
| 1880 | /* |
| 1881 | * Make sure things are in boundary, separate checks |
| 1882 | * are to protect against overflow. |
| 1883 | */ |
| 1884 | err = -ENOMEM; |
| 1885 | if (in_iovs > FUSE_IOCTL_MAX_IOV || |
| 1886 | out_iovs > FUSE_IOCTL_MAX_IOV || |
| 1887 | in_iovs + out_iovs > FUSE_IOCTL_MAX_IOV) |
| 1888 | goto out; |
| 1889 | |
| 1890 | vaddr = kmap_atomic(pages[0], KM_USER0); |
| 1891 | err = fuse_copy_ioctl_iovec(fc, iov_page, vaddr, |
| 1892 | transferred, in_iovs + out_iovs, |
| 1893 | (flags & FUSE_IOCTL_COMPAT) != 0); |
| 1894 | kunmap_atomic(vaddr, KM_USER0); |
| 1895 | if (err) |
| 1896 | goto out; |
| 1897 | |
| 1898 | in_iov = iov_page; |
| 1899 | out_iov = in_iov + in_iovs; |
| 1900 | |
| 1901 | err = fuse_verify_ioctl_iov(in_iov, in_iovs); |
| 1902 | if (err) |
| 1903 | goto out; |
| 1904 | |
| 1905 | err = fuse_verify_ioctl_iov(out_iov, out_iovs); |
| 1906 | if (err) |
| 1907 | goto out; |
| 1908 | |
| 1909 | goto retry; |
| 1910 | } |
| 1911 | |
| 1912 | err = -EIO; |
| 1913 | if (transferred > inarg.out_size) |
| 1914 | goto out; |
| 1915 | |
| 1916 | err = fuse_ioctl_copy_user(pages, out_iov, out_iovs, transferred, true); |
| 1917 | out: |
| 1918 | if (req) |
| 1919 | fuse_put_request(fc, req); |
| 1920 | free_page((unsigned long) iov_page); |
| 1921 | while (num_pages) |
| 1922 | __free_page(pages[--num_pages]); |
| 1923 | kfree(pages); |
| 1924 | |
| 1925 | return err ? err : outarg.result; |
| 1926 | } |
| 1927 | EXPORT_SYMBOL_GPL(fuse_do_ioctl); |
| 1928 | |
| 1929 | long fuse_ioctl_common(struct file *file, unsigned int cmd, |
| 1930 | unsigned long arg, unsigned int flags) |
| 1931 | { |
| 1932 | struct inode *inode = file->f_dentry->d_inode; |
| 1933 | struct fuse_conn *fc = get_fuse_conn(inode); |
| 1934 | |
| 1935 | if (!fuse_allow_task(fc, current)) |
| 1936 | return -EACCES; |
| 1937 | |
| 1938 | if (is_bad_inode(inode)) |
| 1939 | return -EIO; |
| 1940 | |
| 1941 | return fuse_do_ioctl(file, cmd, arg, flags); |
| 1942 | } |
| 1943 | |
| 1944 | static long fuse_file_ioctl(struct file *file, unsigned int cmd, |
| 1945 | unsigned long arg) |
| 1946 | { |
| 1947 | return fuse_ioctl_common(file, cmd, arg, 0); |
| 1948 | } |
| 1949 | |
| 1950 | static long fuse_file_compat_ioctl(struct file *file, unsigned int cmd, |
| 1951 | unsigned long arg) |
| 1952 | { |
| 1953 | return fuse_ioctl_common(file, cmd, arg, FUSE_IOCTL_COMPAT); |
| 1954 | } |
| 1955 | |
| 1956 | /* |
| 1957 | * All files which have been polled are linked to RB tree |
| 1958 | * fuse_conn->polled_files which is indexed by kh. Walk the tree and |
| 1959 | * find the matching one. |
| 1960 | */ |
| 1961 | static struct rb_node **fuse_find_polled_node(struct fuse_conn *fc, u64 kh, |
| 1962 | struct rb_node **parent_out) |
| 1963 | { |
| 1964 | struct rb_node **link = &fc->polled_files.rb_node; |
| 1965 | struct rb_node *last = NULL; |
| 1966 | |
| 1967 | while (*link) { |
| 1968 | struct fuse_file *ff; |
| 1969 | |
| 1970 | last = *link; |
| 1971 | ff = rb_entry(last, struct fuse_file, polled_node); |
| 1972 | |
| 1973 | if (kh < ff->kh) |
| 1974 | link = &last->rb_left; |
| 1975 | else if (kh > ff->kh) |
| 1976 | link = &last->rb_right; |
| 1977 | else |
| 1978 | return link; |
| 1979 | } |
| 1980 | |
| 1981 | if (parent_out) |
| 1982 | *parent_out = last; |
| 1983 | return link; |
| 1984 | } |
| 1985 | |
| 1986 | /* |
| 1987 | * The file is about to be polled. Make sure it's on the polled_files |
| 1988 | * RB tree. Note that files once added to the polled_files tree are |
| 1989 | * not removed before the file is released. This is because a file |
| 1990 | * polled once is likely to be polled again. |
| 1991 | */ |
| 1992 | static void fuse_register_polled_file(struct fuse_conn *fc, |
| 1993 | struct fuse_file *ff) |
| 1994 | { |
| 1995 | spin_lock(&fc->lock); |
| 1996 | if (RB_EMPTY_NODE(&ff->polled_node)) { |
| 1997 | struct rb_node **link, *parent; |
| 1998 | |
| 1999 | link = fuse_find_polled_node(fc, ff->kh, &parent); |
| 2000 | BUG_ON(*link); |
| 2001 | rb_link_node(&ff->polled_node, parent, link); |
| 2002 | rb_insert_color(&ff->polled_node, &fc->polled_files); |
| 2003 | } |
| 2004 | spin_unlock(&fc->lock); |
| 2005 | } |
| 2006 | |
| 2007 | unsigned fuse_file_poll(struct file *file, poll_table *wait) |
| 2008 | { |
| 2009 | struct fuse_file *ff = file->private_data; |
| 2010 | struct fuse_conn *fc = ff->fc; |
| 2011 | struct fuse_poll_in inarg = { .fh = ff->fh, .kh = ff->kh }; |
| 2012 | struct fuse_poll_out outarg; |
| 2013 | struct fuse_req *req; |
| 2014 | int err; |
| 2015 | |
| 2016 | if (fc->no_poll) |
| 2017 | return DEFAULT_POLLMASK; |
| 2018 | |
| 2019 | poll_wait(file, &ff->poll_wait, wait); |
| 2020 | |
| 2021 | /* |
| 2022 | * Ask for notification iff there's someone waiting for it. |
| 2023 | * The client may ignore the flag and always notify. |
| 2024 | */ |
| 2025 | if (waitqueue_active(&ff->poll_wait)) { |
| 2026 | inarg.flags |= FUSE_POLL_SCHEDULE_NOTIFY; |
| 2027 | fuse_register_polled_file(fc, ff); |
| 2028 | } |
| 2029 | |
| 2030 | req = fuse_get_req(fc); |
| 2031 | if (IS_ERR(req)) |
| 2032 | return POLLERR; |
| 2033 | |
| 2034 | req->in.h.opcode = FUSE_POLL; |
| 2035 | req->in.h.nodeid = ff->nodeid; |
| 2036 | req->in.numargs = 1; |
| 2037 | req->in.args[0].size = sizeof(inarg); |
| 2038 | req->in.args[0].value = &inarg; |
| 2039 | req->out.numargs = 1; |
| 2040 | req->out.args[0].size = sizeof(outarg); |
| 2041 | req->out.args[0].value = &outarg; |
| 2042 | fuse_request_send(fc, req); |
| 2043 | err = req->out.h.error; |
| 2044 | fuse_put_request(fc, req); |
| 2045 | |
| 2046 | if (!err) |
| 2047 | return outarg.revents; |
| 2048 | if (err == -ENOSYS) { |
| 2049 | fc->no_poll = 1; |
| 2050 | return DEFAULT_POLLMASK; |
| 2051 | } |
| 2052 | return POLLERR; |
| 2053 | } |
| 2054 | EXPORT_SYMBOL_GPL(fuse_file_poll); |
| 2055 | |
| 2056 | /* |
| 2057 | * This is called from fuse_handle_notify() on FUSE_NOTIFY_POLL and |
| 2058 | * wakes up the poll waiters. |
| 2059 | */ |
| 2060 | int fuse_notify_poll_wakeup(struct fuse_conn *fc, |
| 2061 | struct fuse_notify_poll_wakeup_out *outarg) |
| 2062 | { |
| 2063 | u64 kh = outarg->kh; |
| 2064 | struct rb_node **link; |
| 2065 | |
| 2066 | spin_lock(&fc->lock); |
| 2067 | |
| 2068 | link = fuse_find_polled_node(fc, kh, NULL); |
| 2069 | if (*link) { |
| 2070 | struct fuse_file *ff; |
| 2071 | |
| 2072 | ff = rb_entry(*link, struct fuse_file, polled_node); |
| 2073 | wake_up_interruptible_sync(&ff->poll_wait); |
| 2074 | } |
| 2075 | |
| 2076 | spin_unlock(&fc->lock); |
| 2077 | return 0; |
| 2078 | } |
| 2079 | |
| 2080 | static const struct file_operations fuse_file_operations = { |
| 2081 | .llseek = fuse_file_llseek, |
| 2082 | .read = do_sync_read, |
| 2083 | .aio_read = fuse_file_aio_read, |
| 2084 | .write = do_sync_write, |
| 2085 | .aio_write = fuse_file_aio_write, |
| 2086 | .mmap = fuse_file_mmap, |
| 2087 | .open = fuse_open, |
| 2088 | .flush = fuse_flush, |
| 2089 | .release = fuse_release, |
| 2090 | .fsync = fuse_fsync, |
| 2091 | .lock = fuse_file_lock, |
| 2092 | .flock = fuse_file_flock, |
| 2093 | .splice_read = generic_file_splice_read, |
| 2094 | .unlocked_ioctl = fuse_file_ioctl, |
| 2095 | .compat_ioctl = fuse_file_compat_ioctl, |
| 2096 | .poll = fuse_file_poll, |
| 2097 | }; |
| 2098 | |
| 2099 | static const struct file_operations fuse_direct_io_file_operations = { |
| 2100 | .llseek = fuse_file_llseek, |
| 2101 | .read = fuse_direct_read, |
| 2102 | .write = fuse_direct_write, |
| 2103 | .mmap = fuse_direct_mmap, |
| 2104 | .open = fuse_open, |
| 2105 | .flush = fuse_flush, |
| 2106 | .release = fuse_release, |
| 2107 | .fsync = fuse_fsync, |
| 2108 | .lock = fuse_file_lock, |
| 2109 | .flock = fuse_file_flock, |
| 2110 | .unlocked_ioctl = fuse_file_ioctl, |
| 2111 | .compat_ioctl = fuse_file_compat_ioctl, |
| 2112 | .poll = fuse_file_poll, |
| 2113 | /* no splice_read */ |
| 2114 | }; |
| 2115 | |
| 2116 | static const struct address_space_operations fuse_file_aops = { |
| 2117 | .readpage = fuse_readpage, |
| 2118 | .writepage = fuse_writepage, |
| 2119 | .launder_page = fuse_launder_page, |
| 2120 | .readpages = fuse_readpages, |
| 2121 | .set_page_dirty = __set_page_dirty_nobuffers, |
| 2122 | .bmap = fuse_bmap, |
| 2123 | }; |
| 2124 | |
| 2125 | void fuse_init_file_inode(struct inode *inode) |
| 2126 | { |
| 2127 | inode->i_fop = &fuse_file_operations; |
| 2128 | inode->i_data.a_ops = &fuse_file_aops; |
| 2129 | } |