/* BlockDriver implementation for "raw" * * Copyright (C) 2010, 2013, Red Hat, Inc. * Copyright (C) 2010, Blue Swirl <blauwirbel@gmail.com> * Copyright (C) 2009, Anthony Liguori <aliguori@us.ibm.com> * * Author: * Laszlo Ersek <lersek@redhat.com> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to * deal in the Software without restriction, including without limitation the * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include "block/block_int.h" #include "qemu/option.h" static QemuOptsList raw_create_opts = { .name = "raw-create-opts", .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head), .desc = { { .name = BLOCK_OPT_SIZE, .type = QEMU_OPT_SIZE, .help = "Virtual disk size" }, { /* end of list */ } } }; static int raw_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, Error **errp) { return 0; } static int coroutine_fn raw_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); return bdrv_co_readv(bs->file, sector_num, nb_sectors, qiov); } static int coroutine_fn raw_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { void *buf = NULL; BlockDriver *drv; QEMUIOVector local_qiov; int ret; if (bs->probed && sector_num == 0) { /* As long as these conditions are true, we can't get partial writes to * the probe buffer and can just directly check the request. */ QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512); QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512); if (nb_sectors == 0) { /* qemu_iovec_to_buf() would fail, but we want to return success * instead of -EINVAL in this case. */ return 0; } buf = qemu_try_blockalign(bs->file, 512); if (!buf) { ret = -ENOMEM; goto fail; } ret = qemu_iovec_to_buf(qiov, 0, buf, 512); if (ret != 512) { ret = -EINVAL; goto fail; } drv = bdrv_probe_all(buf, 512, NULL); if (drv != bs->drv) { ret = -EPERM; goto fail; } /* Use the checked buffer, a malicious guest might be overwriting its * original buffer in the background. */ qemu_iovec_init(&local_qiov, qiov->niov + 1); qemu_iovec_add(&local_qiov, buf, 512); qemu_iovec_concat(&local_qiov, qiov, 512, qiov->size - 512); qiov = &local_qiov; } BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); ret = bdrv_co_writev(bs->file, sector_num, nb_sectors, qiov); fail: if (qiov == &local_qiov) { qemu_iovec_destroy(&local_qiov); } qemu_vfree(buf); return ret; } static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { *pnum = nb_sectors; return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA | (sector_num << BDRV_SECTOR_BITS); } static int coroutine_fn raw_co_write_zeroes(BlockDriverState *bs, int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) { return bdrv_co_write_zeroes(bs->file, sector_num, nb_sectors, flags); } static int coroutine_fn raw_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { return bdrv_co_discard(bs->file, sector_num, nb_sectors); } static int64_t raw_getlength(BlockDriverState *bs) { return bdrv_getlength(bs->file); } static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { return bdrv_get_info(bs->file, bdi); } static void raw_refresh_limits(BlockDriverState *bs, Error **errp) { bs->bl = bs->file->bl; } static int raw_truncate(BlockDriverState *bs, int64_t offset) { return bdrv_truncate(bs->file, offset); } static int raw_is_inserted(BlockDriverState *bs) { return bdrv_is_inserted(bs->file); } static int raw_media_changed(BlockDriverState *bs) { return bdrv_media_changed(bs->file); } static void raw_eject(BlockDriverState *bs, bool eject_flag) { bdrv_eject(bs->file, eject_flag); } static void raw_lock_medium(BlockDriverState *bs, bool locked) { bdrv_lock_medium(bs->file, locked); } static int raw_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) { return bdrv_ioctl(bs->file, req, buf); } static BlockAIOCB *raw_aio_ioctl(BlockDriverState *bs, unsigned long int req, void *buf, BlockCompletionFunc *cb, void *opaque) { return bdrv_aio_ioctl(bs->file, req, buf, cb, opaque); } static int raw_has_zero_init(BlockDriverState *bs) { return bdrv_has_zero_init(bs->file); } static int raw_create(const char *filename, QemuOpts *opts, Error **errp) { Error *local_err = NULL; int ret; ret = bdrv_create_file(filename, opts, &local_err); if (local_err) { error_propagate(errp, local_err); } return ret; } static int raw_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { bs->sg = bs->file->sg; if (bs->probed && !bdrv_is_read_only(bs)) { fprintf(stderr, "WARNING: Image format was not specified for '%s' and probing " "guessed raw.\n" " Automatically detecting the format is dangerous for " "raw images, write operations on block 0 will be restricted.\n" " Specify the 'raw' format explicitly to remove the " "restrictions.\n", bs->file->filename); } return 0; } static void raw_close(BlockDriverState *bs) { } static int raw_probe(const uint8_t *buf, int buf_size, const char *filename) { /* smallest possible positive score so that raw is used if and only if no * other block driver works */ return 1; } BlockDriver bdrv_raw = { .format_name = "raw", .bdrv_probe = &raw_probe, .bdrv_reopen_prepare = &raw_reopen_prepare, .bdrv_open = &raw_open, .bdrv_close = &raw_close, .bdrv_create = &raw_create, .bdrv_co_readv = &raw_co_readv, .bdrv_co_writev = &raw_co_writev, .bdrv_co_write_zeroes = &raw_co_write_zeroes, .bdrv_co_discard = &raw_co_discard, .bdrv_co_get_block_status = &raw_co_get_block_status, .bdrv_truncate = &raw_truncate, .bdrv_getlength = &raw_getlength, .has_variable_length = true, .bdrv_get_info = &raw_get_info, .bdrv_refresh_limits = &raw_refresh_limits, .bdrv_is_inserted = &raw_is_inserted, .bdrv_media_changed = &raw_media_changed, .bdrv_eject = &raw_eject, .bdrv_lock_medium = &raw_lock_medium, .bdrv_ioctl = &raw_ioctl, .bdrv_aio_ioctl = &raw_aio_ioctl, .create_opts = &raw_create_opts, .bdrv_has_zero_init = &raw_has_zero_init }; static void bdrv_raw_init(void) { bdrv_register(&bdrv_raw); } block_init(bdrv_raw_init);