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-rw-r--r--fs/notify/fanotify/fanotify_user.c185
1 files changed, 133 insertions, 52 deletions
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 05351936a725..cb7a0c5ff854 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -295,31 +295,83 @@ out:
295 return ret; 295 return ret;
296} 296}
297 297
298static int fanotify_remove_mark(struct fsnotify_group *group, 298static void fanotify_update_object_mask(struct fsnotify_group *group,
299 struct inode *inode, 299 struct inode *inode,
300 __u32 mask) 300 struct vfsmount *mnt,
301 struct fsnotify_mark *fsn_mark,
302 unsigned int flags,
303 __u32 mask)
301{ 304{
302 struct fsnotify_mark *fsn_mark; 305 __u32 old_mask, new_mask;
303 __u32 new_mask;
304
305 pr_debug("%s: group=%p inode=%p mask=%x\n", __func__,
306 group, inode, mask);
307 306
308 fsn_mark = fsnotify_find_inode_mark(group, inode); 307 pr_debug("%s: group=%p inode=%p mnt=%p fsn_mark=%p flags=%x mask=%x\n",
309 if (!fsn_mark) 308 __func__, group, inode, mnt, fsn_mark, flags, mask);
310 return -ENOENT;
311 309
312 spin_lock(&fsn_mark->lock); 310 spin_lock(&fsn_mark->lock);
313 fsn_mark->mask &= ~mask; 311 old_mask = fsn_mark->mask;
312 if (flags & FAN_MARK_ADD)
313 fsn_mark->mask |= mask;
314 else if (flags & FAN_MARK_REMOVE)
315 fsn_mark->mask &= ~mask;
316 else
317 BUG();
314 new_mask = fsn_mark->mask; 318 new_mask = fsn_mark->mask;
315 spin_unlock(&fsn_mark->lock); 319 spin_unlock(&fsn_mark->lock);
316 320
317 if (!new_mask) 321 if (!new_mask)
318 fsnotify_destroy_mark(fsn_mark); 322 fsnotify_destroy_mark(fsn_mark);
323
324 /* we made changes to a mask, update the group mask and the object mask
325 * so things happen quickly. */
326 if (old_mask != new_mask) {
327 __u32 dropped, do_object, do_group;
328
329 /* more bits in old than in new? */
330 dropped = (old_mask & ~new_mask);
331 /* more bits in this fsn_mark than the group? */
332 do_group = (new_mask & ~group->mask);
333
334 if (inode) {
335 /* more bits in this fsn_mark than the object's mask? */
336 do_object = (new_mask & ~inode->i_fsnotify_mask);
337 /* update the object with this new fsn_mark */
338 if (dropped || do_object)
339 fsnotify_recalc_inode_mask(inode);
340 } else if (mnt) {
341 /* more bits in this fsn_mark than the object's mask? */
342 do_object = (new_mask & ~mnt->mnt_fsnotify_mask);
343 /* update the object with this new fsn_mark */
344 if (dropped || do_object)
345 fsnotify_recalc_vfsmount_mask(mnt);
346 } else {
347 BUG();
348 }
349
350 /* update the group mask with the new mask */
351 if (dropped || do_group)
352 fsnotify_recalc_group_mask(group);
353 }
354}
355
356static int fanotify_remove_mark(struct fsnotify_group *group, struct inode *inode,
357 struct vfsmount *mnt, unsigned int flags, __u32 mask)
358{
359 struct fsnotify_mark *fsn_mark = NULL;
360
361 BUG_ON(inode && mnt);
362 BUG_ON(!inode && !mnt);
363
364 if (inode)
365 fsn_mark = fsnotify_find_inode_mark(group, inode);
366 else if (mnt)
367 fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
319 else 368 else
320 fsnotify_recalc_inode_mask(inode); 369 BUG();
321 370
322 fsnotify_recalc_group_mask(group); 371 if (!fsn_mark)
372 return -ENOENT;
373
374 fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask);
323 375
324 /* matches the fsnotify_find_inode_mark() */ 376 /* matches the fsnotify_find_inode_mark() */
325 fsnotify_put_mark(fsn_mark); 377 fsnotify_put_mark(fsn_mark);
@@ -327,22 +379,48 @@ static int fanotify_remove_mark(struct fsnotify_group *group,
327 return 0; 379 return 0;
328} 380}
329 381
330static int fanotify_add_mark(struct fsnotify_group *group, 382static struct fsnotify_mark *fanotify_add_vfsmount_mark(struct fsnotify_group *group,
331 struct inode *inode, 383 struct vfsmount *mnt)
332 __u32 mask)
333{ 384{
334 struct fsnotify_mark *fsn_mark; 385 struct fsnotify_mark *fsn_mark;
335 __u32 old_mask, new_mask;
336 int ret;
337 386
338 pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, 387 fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
339 group, inode, mask); 388 if (!fsn_mark) {
389 struct fsnotify_mark *new_fsn_mark;
390 int ret;
391
392 fsn_mark = ERR_PTR(-ENOMEM);
393 new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
394 if (!new_fsn_mark)
395 goto out;
396
397 fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
398 ret = fsnotify_add_mark(new_fsn_mark, group, NULL, mnt, 0);
399 if (ret) {
400 fsn_mark = ERR_PTR(ret);
401 fanotify_free_mark(new_fsn_mark);
402 goto out;
403 }
404
405 fsn_mark = new_fsn_mark;
406 }
407out:
408 return fsn_mark;
409}
410
411static struct fsnotify_mark *fanotify_add_inode_mark(struct fsnotify_group *group,
412 struct inode *inode)
413{
414 struct fsnotify_mark *fsn_mark;
415
416 pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
340 417
341 fsn_mark = fsnotify_find_inode_mark(group, inode); 418 fsn_mark = fsnotify_find_inode_mark(group, inode);
342 if (!fsn_mark) { 419 if (!fsn_mark) {
343 struct fsnotify_mark *new_fsn_mark; 420 struct fsnotify_mark *new_fsn_mark;
421 int ret;
344 422
345 ret = -ENOMEM; 423 fsn_mark = ERR_PTR(-ENOMEM);
346 new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL); 424 new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
347 if (!new_fsn_mark) 425 if (!new_fsn_mark)
348 goto out; 426 goto out;
@@ -350,57 +428,60 @@ static int fanotify_add_mark(struct fsnotify_group *group,
350 fsnotify_init_mark(new_fsn_mark, fanotify_free_mark); 428 fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
351 ret = fsnotify_add_mark(new_fsn_mark, group, inode, NULL, 0); 429 ret = fsnotify_add_mark(new_fsn_mark, group, inode, NULL, 0);
352 if (ret) { 430 if (ret) {
431 fsn_mark = ERR_PTR(ret);
353 fanotify_free_mark(new_fsn_mark); 432 fanotify_free_mark(new_fsn_mark);
354 goto out; 433 goto out;
355 } 434 }
356 435
357 fsn_mark = new_fsn_mark; 436 fsn_mark = new_fsn_mark;
358 } 437 }
438out:
439 return fsn_mark;
440}
359 441
360 ret = 0; 442static int fanotify_add_mark(struct fsnotify_group *group, struct inode *inode,
443 struct vfsmount *mnt, unsigned int flags, __u32 mask)
444{
445 struct fsnotify_mark *fsn_mark;
361 446
362 spin_lock(&fsn_mark->lock); 447 pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n",
363 old_mask = fsn_mark->mask; 448 __func__, group, inode, mnt, flags, mask);
364 fsn_mark->mask |= mask;
365 new_mask = fsn_mark->mask;
366 spin_unlock(&fsn_mark->lock);
367 449
368 /* we made changes to a mask, update the group mask and the inode mask 450 BUG_ON(inode && mnt);
369 * so things happen quickly. */ 451 BUG_ON(!inode && !mnt);
370 if (old_mask != new_mask) {
371 /* more bits in old than in new? */
372 int dropped = (old_mask & ~new_mask);
373 /* more bits in this mark than the inode's mask? */
374 int do_inode = (new_mask & ~inode->i_fsnotify_mask);
375 /* more bits in this mark than the group? */
376 int do_group = (new_mask & ~group->mask);
377 452
378 /* update the inode with this new mark */ 453 if (inode)
379 if (dropped || do_inode) 454 fsn_mark = fanotify_add_inode_mark(group, inode);
380 fsnotify_recalc_inode_mask(inode); 455 else if (mnt)
456 fsn_mark = fanotify_add_vfsmount_mark(group, mnt);
457 else
458 BUG();
381 459
382 /* update the group mask with the new mask */ 460 if (IS_ERR(fsn_mark))
383 if (dropped || do_group) 461 goto out;
384 fsnotify_recalc_group_mask(group); 462
385 } 463 fanotify_update_object_mask(group, inode, mnt, fsn_mark, flags, mask);
386 464
387 /* match the init or the find.... */ 465 /* match the init or the find.... */
388 fsnotify_put_mark(fsn_mark); 466 fsnotify_put_mark(fsn_mark);
389out: 467out:
390 return ret; 468 return PTR_ERR(fsn_mark);
391} 469}
392 470
393static int fanotify_update_mark(struct fsnotify_group *group, 471static int fanotify_update_mark(struct fsnotify_group *group,
394 struct inode *inode, int flags, 472 struct inode *inode, struct vfsmount *mnt,
395 __u32 mask) 473 int flags, __u32 mask)
396{ 474{
397 pr_debug("%s: group=%p inode=%p flags=%x mask=%x\n", __func__, 475 pr_debug("%s: group=%p inode=%p mnt=%p flags=%x mask=%x\n",
398 group, inode, flags, mask); 476 __func__, group, inode, mnt, flags, mask);
477
478 BUG_ON(inode && mnt);
479 BUG_ON(!inode && !mnt);
399 480
400 if (flags & FAN_MARK_ADD) 481 if (flags & FAN_MARK_ADD)
401 fanotify_add_mark(group, inode, mask); 482 fanotify_add_mark(group, inode, mnt, flags, mask);
402 else if (flags & FAN_MARK_REMOVE) 483 else if (flags & FAN_MARK_REMOVE)
403 fanotify_remove_mark(group, inode, mask); 484 fanotify_remove_mark(group, inode, mnt, flags, mask);
404 else 485 else
405 BUG(); 486 BUG();
406 487
@@ -502,7 +583,7 @@ SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
502 group = filp->private_data; 583 group = filp->private_data;
503 584
504 /* create/update an inode mark */ 585 /* create/update an inode mark */
505 ret = fanotify_update_mark(group, inode, flags, mask); 586 ret = fanotify_update_mark(group, inode, NULL, flags, mask);
506 587
507 path_put(&path); 588 path_put(&path);
508fput_and_out: 589fput_and_out: