block: Rename raw_bsd to raw-format.c

Given that we have raw-win32.c and raw-posix.c, my initial guess at
raw_bsd.c was that it was for dealing with raw files using code
specific to the BSD operating system (beyond what raw-posix could
do).  Not so - this name was chosen back in commit e1c66c6 to
distinguish that it was a BSD licensed file, in contrast to the
then-existing raw.c with an unclear and potentially unusable
license.  But since it has been more than three years since the
rewrite, it's time to pick a more useful name for this file to
avoid this type of confusion to future contributors that don't know
the backstory, as none of our other files are named solely by the
license they use.

In reality, this file deals with the raw format, which is useful
with any number of protocols, while raw-{win32,posix} deal with
the file protocol (and in turn, that protocol is not limited to
use with the raw format).  So rename raw_bsd to raw-format.c.  We
could have also used the shorter name raw.c, except that collides
with the earlier use of that filename for a different license,
and it's better to be safe than risk license pollution.

The next patch will also rename raw-win32.c and raw-posix.c to
further distinguish the difference in roles.

It doesn't hurt that this gets rid of an underscore in the filename,
thereby making tab-completion on 'ra<TAB>' easier (now I don't have
to type the shift key, which slows things down :)

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 490 insertions, 0 deletions

diff --git a/block/raw-format.c b/block/raw-format.c
new file mode 100644
index 0000000000..8404a82e0c
--- /dev/null
+++ b/block/raw-format.c
@@ -0,0 +1,490 @@
+/* BlockDriver implementation for "raw" format driver
+ *
+ * Copyright (C) 2010-2016 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 "qemu/osdep.h"
+#include "block/block_int.h"
+#include "qapi/error.h"
+#include "qemu/option.h"
+
+typedef struct BDRVRawState {
+    uint64_t offset;
+    uint64_t size;
+    bool has_size;
+} BDRVRawState;
+
+static QemuOptsList raw_runtime_opts = {
+    .name = "raw",
+    .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
+    .desc = {
+        {
+            .name = "offset",
+            .type = QEMU_OPT_SIZE,
+            .help = "offset in the disk where the image starts",
+        },
+        {
+            .name = "size",
+            .type = QEMU_OPT_SIZE,
+            .help = "virtual disk size",
+        },
+        { /* end of list */ }
+    },
+};
+
+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_read_options(QDict *options, BlockDriverState *bs,
+    BDRVRawState *s, Error **errp)
+{
+    Error *local_err = NULL;
+    QemuOpts *opts = NULL;
+    int64_t real_size = 0;
+    int ret;
+
+    real_size = bdrv_getlength(bs->file->bs);
+    if (real_size < 0) {
+        error_setg_errno(errp, -real_size, "Could not get image size");
+        return real_size;
+    }
+
+    opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
+    qemu_opts_absorb_qdict(opts, options, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto end;
+    }
+
+    s->offset = qemu_opt_get_size(opts, "offset", 0);
+    if (s->offset > real_size) {
+        error_setg(errp, "Offset (%" PRIu64 ") cannot be greater than "
+            "size of the containing file (%" PRId64 ")",
+            s->offset, real_size);
+        ret = -EINVAL;
+        goto end;
+    }
+
+    if (qemu_opt_find(opts, "size") != NULL) {
+        s->size = qemu_opt_get_size(opts, "size", 0);
+        s->has_size = true;
+    } else {
+        s->has_size = false;
+        s->size = real_size - s->offset;
+    }
+
+    /* Check size and offset */
+    if ((real_size - s->offset) < s->size) {
+        error_setg(errp, "The sum of offset (%" PRIu64 ") and size "
+            "(%" PRIu64 ") has to be smaller or equal to the "
+            " actual size of the containing file (%" PRId64 ")",
+            s->offset, s->size, real_size);
+        ret = -EINVAL;
+        goto end;
+    }
+
+    /* Make sure size is multiple of BDRV_SECTOR_SIZE to prevent rounding
+     * up and leaking out of the specified area. */
+    if (s->has_size && !QEMU_IS_ALIGNED(s->size, BDRV_SECTOR_SIZE)) {
+        error_setg(errp, "Specified size is not multiple of %llu",
+            BDRV_SECTOR_SIZE);
+        ret = -EINVAL;
+        goto end;
+    }
+
+    ret = 0;
+
+end:
+
+    qemu_opts_del(opts);
+
+    return ret;
+}
+
+static int raw_reopen_prepare(BDRVReopenState *reopen_state,
+                              BlockReopenQueue *queue, Error **errp)
+{
+    assert(reopen_state != NULL);
+    assert(reopen_state->bs != NULL);
+
+    reopen_state->opaque = g_new0(BDRVRawState, 1);
+
+    return raw_read_options(
+        reopen_state->options,
+        reopen_state->bs,
+        reopen_state->opaque,
+        errp);
+}
+
+static void raw_reopen_commit(BDRVReopenState *state)
+{
+    BDRVRawState *new_s = state->opaque;
+    BDRVRawState *s = state->bs->opaque;
+
+    memcpy(s, new_s, sizeof(BDRVRawState));
+
+    g_free(state->opaque);
+    state->opaque = NULL;
+}
+
+static void raw_reopen_abort(BDRVReopenState *state)
+{
+    g_free(state->opaque);
+    state->opaque = NULL;
+}
+
+static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,
+                                      uint64_t bytes, QEMUIOVector *qiov,
+                                      int flags)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (offset > UINT64_MAX - s->offset) {
+        return -EINVAL;
+    }
+    offset += s->offset;
+
+    BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+    return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
+}
+
+static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
+                                       uint64_t bytes, QEMUIOVector *qiov,
+                                       int flags)
+{
+    BDRVRawState *s = bs->opaque;
+    void *buf = NULL;
+    BlockDriver *drv;
+    QEMUIOVector local_qiov;
+    int ret;
+
+    if (s->has_size && (offset > s->size || bytes > (s->size - offset))) {
+        /* There's not enough space for the data. Don't write anything and just
+         * fail to prevent leaking out of the size specified in options. */
+        return -ENOSPC;
+    }
+
+    if (offset > UINT64_MAX - s->offset) {
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    if (bs->probed && offset < BLOCK_PROBE_BUF_SIZE && bytes) {
+        /* Handling partial writes would be a pain - so we just
+         * require that guests have 512-byte request alignment if
+         * probing occurred */
+        QEMU_BUILD_BUG_ON(BLOCK_PROBE_BUF_SIZE != 512);
+        QEMU_BUILD_BUG_ON(BDRV_SECTOR_SIZE != 512);
+        assert(offset == 0 && bytes >= BLOCK_PROBE_BUF_SIZE);
+
+        buf = qemu_try_blockalign(bs->file->bs, 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;
+    }
+
+    offset += s->offset;
+
+    BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+    ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
+
+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,
+                                            BlockDriverState **file)
+{
+    BDRVRawState *s = bs->opaque;
+    *pnum = nb_sectors;
+    *file = bs->file->bs;
+    sector_num += s->offset / BDRV_SECTOR_SIZE;
+    return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA |
+           (sector_num << BDRV_SECTOR_BITS);
+}
+
+static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
+                                             int64_t offset, int count,
+                                             BdrvRequestFlags flags)
+{
+    BDRVRawState *s = bs->opaque;
+    if (offset > UINT64_MAX - s->offset) {
+        return -EINVAL;
+    }
+    offset += s->offset;
+    return bdrv_co_pwrite_zeroes(bs->file, offset, count, flags);
+}
+
+static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
+                                        int64_t offset, int count)
+{
+    BDRVRawState *s = bs->opaque;
+    if (offset > UINT64_MAX - s->offset) {
+        return -EINVAL;
+    }
+    offset += s->offset;
+    return bdrv_co_pdiscard(bs->file->bs, offset, count);
+}
+
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    int64_t len;
+    BDRVRawState *s = bs->opaque;
+
+    /* Update size. It should not change unless the file was externally
+     * modified. */
+    len = bdrv_getlength(bs->file->bs);
+    if (len < 0) {
+        return len;
+    }
+
+    if (len < s->offset) {
+        s->size = 0;
+    } else {
+        if (s->has_size) {
+            /* Try to honour the size */
+            s->size = MIN(s->size, len - s->offset);
+        } else {
+            s->size = len - s->offset;
+        }
+    }
+
+    return s->size;
+}
+
+static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+    return bdrv_get_info(bs->file->bs, bdi);
+}
+
+static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    if (bs->probed) {
+        /* To make it easier to protect the first sector, any probed
+         * image is restricted to read-modify-write on sub-sector
+         * operations. */
+        bs->bl.request_alignment = BDRV_SECTOR_SIZE;
+    }
+}
+
+static int raw_truncate(BlockDriverState *bs, int64_t offset)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->has_size) {
+        return -ENOTSUP;
+    }
+
+    if (INT64_MAX - offset < s->offset) {
+        return -EINVAL;
+    }
+
+    s->size = offset;
+    offset += s->offset;
+    return bdrv_truncate(bs->file->bs, offset);
+}
+
+static int raw_media_changed(BlockDriverState *bs)
+{
+    return bdrv_media_changed(bs->file->bs);
+}
+
+static void raw_eject(BlockDriverState *bs, bool eject_flag)
+{
+    bdrv_eject(bs->file->bs, eject_flag);
+}
+
+static void raw_lock_medium(BlockDriverState *bs, bool locked)
+{
+    bdrv_lock_medium(bs->file->bs, locked);
+}
+
+static int raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
+{
+    BDRVRawState *s = bs->opaque;
+    if (s->offset || s->has_size) {
+        return -ENOTSUP;
+    }
+    return bdrv_co_ioctl(bs->file->bs, req, buf);
+}
+
+static int raw_has_zero_init(BlockDriverState *bs)
+{
+    return bdrv_has_zero_init(bs->file->bs);
+}
+
+static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
+{
+    return bdrv_create_file(filename, opts, errp);
+}
+
+static int raw_open(BlockDriverState *bs, QDict *options, int flags,
+                    Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    int ret;
+
+    bs->sg = bs->file->bs->sg;
+    bs->supported_write_flags = BDRV_REQ_FUA &
+        bs->file->bs->supported_write_flags;
+    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+        bs->file->bs->supported_zero_flags;
+
+    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->bs->filename);
+    }
+
+    ret = raw_read_options(options, bs, s, errp);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (bs->sg && (s->offset || s->has_size)) {
+        error_setg(errp, "Cannot use offset/size with SCSI generic devices");
+        return -EINVAL;
+    }
+
+    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;
+}
+
+static int raw_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
+{
+    BDRVRawState *s = bs->opaque;
+    int ret;
+
+    ret = bdrv_probe_blocksizes(bs->file->bs, bsz);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (!QEMU_IS_ALIGNED(s->offset, MAX(bsz->log, bsz->phys))) {
+        return -ENOTSUP;
+    }
+
+    return 0;
+}
+
+static int raw_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
+{
+    BDRVRawState *s = bs->opaque;
+    if (s->offset || s->has_size) {
+        return -ENOTSUP;
+    }
+    return bdrv_probe_geometry(bs->file->bs, geo);
+}
+
+BlockDriver bdrv_raw = {
+    .format_name          = "raw",
+    .instance_size        = sizeof(BDRVRawState),
+    .bdrv_probe           = &raw_probe,
+    .bdrv_reopen_prepare  = &raw_reopen_prepare,
+    .bdrv_reopen_commit   = &raw_reopen_commit,
+    .bdrv_reopen_abort    = &raw_reopen_abort,
+    .bdrv_open            = &raw_open,
+    .bdrv_close           = &raw_close,
+    .bdrv_create          = &raw_create,
+    .bdrv_co_preadv       = &raw_co_preadv,
+    .bdrv_co_pwritev      = &raw_co_pwritev,
+    .bdrv_co_pwrite_zeroes = &raw_co_pwrite_zeroes,
+    .bdrv_co_pdiscard     = &raw_co_pdiscard,
+    .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_probe_blocksizes = &raw_probe_blocksizes,
+    .bdrv_probe_geometry  = &raw_probe_geometry,
+    .bdrv_media_changed   = &raw_media_changed,
+    .bdrv_eject           = &raw_eject,
+    .bdrv_lock_medium     = &raw_lock_medium,
+    .bdrv_co_ioctl        = &raw_co_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);