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Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/loop.c73
1 files changed, 40 insertions, 33 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d9589017cc1e..018af27256c5 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -417,6 +417,40 @@ lo_receive(struct loop_device *lo, struct request *rq, int bsize, loff_t pos)
417 return 0; 417 return 0;
418} 418}
419 419
420static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos)
421{
422 /*
423 * We use punch hole to reclaim the free space used by the
424 * image a.k.a. discard. However we do not support discard if
425 * encryption is enabled, because it may give an attacker
426 * useful information.
427 */
428 struct file *file = lo->lo_backing_file;
429 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
430 int ret;
431
432 if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) {
433 ret = -EOPNOTSUPP;
434 goto out;
435 }
436
437 ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq));
438 if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
439 ret = -EIO;
440 out:
441 return ret;
442}
443
444static int lo_req_flush(struct loop_device *lo, struct request *rq)
445{
446 struct file *file = lo->lo_backing_file;
447 int ret = vfs_fsync(file, 0);
448 if (unlikely(ret && ret != -EINVAL))
449 ret = -EIO;
450
451 return ret;
452}
453
420static int do_req_filebacked(struct loop_device *lo, struct request *rq) 454static int do_req_filebacked(struct loop_device *lo, struct request *rq)
421{ 455{
422 loff_t pos; 456 loff_t pos;
@@ -425,46 +459,19 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
425 pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; 459 pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset;
426 460
427 if (rq->cmd_flags & REQ_WRITE) { 461 if (rq->cmd_flags & REQ_WRITE) {
428 struct file *file = lo->lo_backing_file;
429
430 if (rq->cmd_flags & REQ_FLUSH) {
431 ret = vfs_fsync(file, 0);
432 if (unlikely(ret && ret != -EINVAL)) {
433 ret = -EIO;
434 goto out;
435 }
436 }
437 462
438 /* 463 if (rq->cmd_flags & REQ_FLUSH)
439 * We use punch hole to reclaim the free space used by the 464 ret = lo_req_flush(lo, rq);
440 * image a.k.a. discard. However we do not support discard if 465
441 * encryption is enabled, because it may give an attacker
442 * useful information.
443 */
444 if (rq->cmd_flags & REQ_DISCARD) { 466 if (rq->cmd_flags & REQ_DISCARD) {
445 struct file *file = lo->lo_backing_file; 467 ret = lo_discard(lo, rq, pos);
446 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
447
448 if ((!file->f_op->fallocate) ||
449 lo->lo_encrypt_key_size) {
450 ret = -EOPNOTSUPP;
451 goto out;
452 }
453 ret = file->f_op->fallocate(file, mode, pos,
454 blk_rq_bytes(rq));
455 if (unlikely(ret && ret != -EINVAL &&
456 ret != -EOPNOTSUPP))
457 ret = -EIO;
458 goto out; 468 goto out;
459 } 469 }
460 470
461 ret = lo_send(lo, rq, pos); 471 ret = lo_send(lo, rq, pos);
462 472
463 if ((rq->cmd_flags & REQ_FUA) && !ret) { 473 if ((rq->cmd_flags & REQ_FUA) && !ret)
464 ret = vfs_fsync(file, 0); 474 ret = lo_req_flush(lo, rq);
465 if (unlikely(ret && ret != -EINVAL))
466 ret = -EIO;
467 }
468 } else 475 } else
469 ret = lo_receive(lo, rq, lo->lo_blocksize, pos); 476 ret = lo_receive(lo, rq, lo->lo_blocksize, pos);
470 477