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/*
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* QEMU System Emulator block driver
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "config-host.h" |
25 |
#include "qemu-common.h" |
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#include "trace.h" |
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#include "monitor/monitor.h" |
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#include "block/block_int.h" |
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#include "block/blockjob.h" |
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#include "qemu/module.h" |
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#include "qapi/qmp/qjson.h" |
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#include "sysemu/sysemu.h" |
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#include "qemu/notify.h" |
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#include "block/coroutine.h" |
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#include "block/qapi.h" |
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#include "qmp-commands.h" |
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#include "qemu/timer.h" |
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|
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#ifdef CONFIG_BSD
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <sys/ioctl.h> |
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#include <sys/queue.h> |
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#ifndef __DragonFly__
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#include <sys/disk.h> |
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#endif
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#endif
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|
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#ifdef _WIN32
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#include <windows.h> |
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#endif
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|
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struct BdrvDirtyBitmap {
|
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HBitmap *bitmap; |
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QLIST_ENTRY(BdrvDirtyBitmap) list; |
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}; |
57 |
|
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#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ |
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|
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static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); |
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static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
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int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
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BlockDriverCompletionFunc *cb, void *opaque);
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static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
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int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
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BlockDriverCompletionFunc *cb, void *opaque);
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static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, |
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int64_t sector_num, int nb_sectors,
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QEMUIOVector *iov); |
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static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, |
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int64_t sector_num, int nb_sectors,
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QEMUIOVector *iov); |
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static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, |
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int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
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BdrvRequestFlags flags); |
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static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, |
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int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
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BdrvRequestFlags flags); |
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static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
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int64_t sector_num, |
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QEMUIOVector *qiov, |
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int nb_sectors,
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BdrvRequestFlags flags, |
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BlockDriverCompletionFunc *cb, |
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void *opaque,
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bool is_write);
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static void coroutine_fn bdrv_co_do_rw(void *opaque); |
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static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, |
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int64_t sector_num, int nb_sectors, BdrvRequestFlags flags);
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static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
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QTAILQ_HEAD_INITIALIZER(bdrv_states); |
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static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
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QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); |
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static QLIST_HEAD(, BlockDriver) bdrv_drivers =
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QLIST_HEAD_INITIALIZER(bdrv_drivers); |
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/* If non-zero, use only whitelisted block drivers */
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static int use_bdrv_whitelist; |
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#ifdef _WIN32
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static int is_windows_drive_prefix(const char *filename) |
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{ |
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return (((filename[0] >= 'a' && filename[0] <= 'z') || |
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(filename[0] >= 'A' && filename[0] <= 'Z')) && |
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filename[1] == ':'); |
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} |
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int is_windows_drive(const char *filename) |
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{ |
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if (is_windows_drive_prefix(filename) &&
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filename[2] == '\0') |
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return 1; |
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if (strstart(filename, "\\\\.\\", NULL) || |
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strstart(filename, "//./", NULL)) |
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return 1; |
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return 0; |
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} |
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#endif
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|
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/* throttling disk I/O limits */
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void bdrv_set_io_limits(BlockDriverState *bs,
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ThrottleConfig *cfg) |
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{ |
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int i;
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throttle_config(&bs->throttle_state, cfg); |
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for (i = 0; i < 2; i++) { |
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qemu_co_enter_next(&bs->throttled_reqs[i]); |
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} |
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} |
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|
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/* this function drain all the throttled IOs */
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static bool bdrv_start_throttled_reqs(BlockDriverState *bs) |
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{ |
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bool drained = false; |
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bool enabled = bs->io_limits_enabled;
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int i;
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bs->io_limits_enabled = false;
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for (i = 0; i < 2; i++) { |
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while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
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drained = true;
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} |
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} |
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bs->io_limits_enabled = enabled; |
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return drained;
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} |
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void bdrv_io_limits_disable(BlockDriverState *bs)
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{ |
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bs->io_limits_enabled = false;
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bdrv_start_throttled_reqs(bs); |
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throttle_destroy(&bs->throttle_state); |
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} |
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static void bdrv_throttle_read_timer_cb(void *opaque) |
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{ |
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BlockDriverState *bs = opaque; |
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qemu_co_enter_next(&bs->throttled_reqs[0]);
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} |
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static void bdrv_throttle_write_timer_cb(void *opaque) |
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{ |
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BlockDriverState *bs = opaque; |
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qemu_co_enter_next(&bs->throttled_reqs[1]);
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} |
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/* should be called before bdrv_set_io_limits if a limit is set */
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void bdrv_io_limits_enable(BlockDriverState *bs)
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{ |
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assert(!bs->io_limits_enabled); |
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throttle_init(&bs->throttle_state, |
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QEMU_CLOCK_VIRTUAL, |
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bdrv_throttle_read_timer_cb, |
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bdrv_throttle_write_timer_cb, |
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bs); |
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bs->io_limits_enabled = true;
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} |
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/* This function makes an IO wait if needed
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*
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* @nb_sectors: the number of sectors of the IO
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* @is_write: is the IO a write
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*/
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static void bdrv_io_limits_intercept(BlockDriverState *bs, |
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int nb_sectors,
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bool is_write)
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{ |
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/* does this io must wait */
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bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write);
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/* if must wait or any request of this type throttled queue the IO */
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if (must_wait ||
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!qemu_co_queue_empty(&bs->throttled_reqs[is_write])) { |
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qemu_co_queue_wait(&bs->throttled_reqs[is_write]); |
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} |
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/* the IO will be executed, do the accounting */
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throttle_account(&bs->throttle_state, |
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is_write, |
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nb_sectors * BDRV_SECTOR_SIZE); |
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/* if the next request must wait -> do nothing */
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if (throttle_schedule_timer(&bs->throttle_state, is_write)) {
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return;
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} |
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/* else queue next request for execution */
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qemu_co_queue_next(&bs->throttled_reqs[is_write]); |
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} |
220 |
|
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/* check if the path starts with "<protocol>:" */
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static int path_has_protocol(const char *path) |
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{ |
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const char *p; |
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#ifdef _WIN32
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if (is_windows_drive(path) ||
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is_windows_drive_prefix(path)) { |
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return 0; |
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} |
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p = path + strcspn(path, ":/\\");
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#else
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p = path + strcspn(path, ":/");
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#endif
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return *p == ':'; |
237 |
} |
238 |
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int path_is_absolute(const char *path) |
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{ |
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#ifdef _WIN32
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/* specific case for names like: "\\.\d:" */
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if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
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return 1; |
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} |
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return (*path == '/' || *path == '\\'); |
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#else
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return (*path == '/'); |
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#endif
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} |
251 |
|
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/* if filename is absolute, just copy it to dest. Otherwise, build a
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path to it by considering it is relative to base_path. URL are
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supported. */
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void path_combine(char *dest, int dest_size, |
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const char *base_path, |
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const char *filename) |
258 |
{ |
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const char *p, *p1; |
260 |
int len;
|
261 |
|
262 |
if (dest_size <= 0) |
263 |
return;
|
264 |
if (path_is_absolute(filename)) {
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pstrcpy(dest, dest_size, filename); |
266 |
} else {
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p = strchr(base_path, ':');
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if (p)
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p++; |
270 |
else
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p = base_path; |
272 |
p1 = strrchr(base_path, '/');
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#ifdef _WIN32
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{ |
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const char *p2; |
276 |
p2 = strrchr(base_path, '\\');
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if (!p1 || p2 > p1)
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p1 = p2; |
279 |
} |
280 |
#endif
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281 |
if (p1)
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p1++; |
283 |
else
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p1 = base_path; |
285 |
if (p1 > p)
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p = p1; |
287 |
len = p - base_path; |
288 |
if (len > dest_size - 1) |
289 |
len = dest_size - 1;
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memcpy(dest, base_path, len); |
291 |
dest[len] = '\0';
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pstrcat(dest, dest_size, filename); |
293 |
} |
294 |
} |
295 |
|
296 |
void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz) |
297 |
{ |
298 |
if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) { |
299 |
pstrcpy(dest, sz, bs->backing_file); |
300 |
} else {
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path_combine(dest, sz, bs->filename, bs->backing_file); |
302 |
} |
303 |
} |
304 |
|
305 |
void bdrv_register(BlockDriver *bdrv)
|
306 |
{ |
307 |
/* Block drivers without coroutine functions need emulation */
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308 |
if (!bdrv->bdrv_co_readv) {
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309 |
bdrv->bdrv_co_readv = bdrv_co_readv_em; |
310 |
bdrv->bdrv_co_writev = bdrv_co_writev_em; |
311 |
|
312 |
/* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if
|
313 |
* the block driver lacks aio we need to emulate that too.
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314 |
*/
|
315 |
if (!bdrv->bdrv_aio_readv) {
|
316 |
/* add AIO emulation layer */
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317 |
bdrv->bdrv_aio_readv = bdrv_aio_readv_em; |
318 |
bdrv->bdrv_aio_writev = bdrv_aio_writev_em; |
319 |
} |
320 |
} |
321 |
|
322 |
QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); |
323 |
} |
324 |
|
325 |
/* create a new block device (by default it is empty) */
|
326 |
BlockDriverState *bdrv_new(const char *device_name) |
327 |
{ |
328 |
BlockDriverState *bs; |
329 |
|
330 |
bs = g_malloc0(sizeof(BlockDriverState));
|
331 |
QLIST_INIT(&bs->dirty_bitmaps); |
332 |
pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
|
333 |
if (device_name[0] != '\0') { |
334 |
QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list); |
335 |
} |
336 |
bdrv_iostatus_disable(bs); |
337 |
notifier_list_init(&bs->close_notifiers); |
338 |
notifier_with_return_list_init(&bs->before_write_notifiers); |
339 |
qemu_co_queue_init(&bs->throttled_reqs[0]);
|
340 |
qemu_co_queue_init(&bs->throttled_reqs[1]);
|
341 |
bs->refcnt = 1;
|
342 |
|
343 |
return bs;
|
344 |
} |
345 |
|
346 |
void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify)
|
347 |
{ |
348 |
notifier_list_add(&bs->close_notifiers, notify); |
349 |
} |
350 |
|
351 |
BlockDriver *bdrv_find_format(const char *format_name) |
352 |
{ |
353 |
BlockDriver *drv1; |
354 |
QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
355 |
if (!strcmp(drv1->format_name, format_name)) {
|
356 |
return drv1;
|
357 |
} |
358 |
} |
359 |
return NULL; |
360 |
} |
361 |
|
362 |
static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) |
363 |
{ |
364 |
static const char *whitelist_rw[] = { |
365 |
CONFIG_BDRV_RW_WHITELIST |
366 |
}; |
367 |
static const char *whitelist_ro[] = { |
368 |
CONFIG_BDRV_RO_WHITELIST |
369 |
}; |
370 |
const char **p; |
371 |
|
372 |
if (!whitelist_rw[0] && !whitelist_ro[0]) { |
373 |
return 1; /* no whitelist, anything goes */ |
374 |
} |
375 |
|
376 |
for (p = whitelist_rw; *p; p++) {
|
377 |
if (!strcmp(drv->format_name, *p)) {
|
378 |
return 1; |
379 |
} |
380 |
} |
381 |
if (read_only) {
|
382 |
for (p = whitelist_ro; *p; p++) {
|
383 |
if (!strcmp(drv->format_name, *p)) {
|
384 |
return 1; |
385 |
} |
386 |
} |
387 |
} |
388 |
return 0; |
389 |
} |
390 |
|
391 |
BlockDriver *bdrv_find_whitelisted_format(const char *format_name, |
392 |
bool read_only)
|
393 |
{ |
394 |
BlockDriver *drv = bdrv_find_format(format_name); |
395 |
return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL; |
396 |
} |
397 |
|
398 |
typedef struct CreateCo { |
399 |
BlockDriver *drv; |
400 |
char *filename;
|
401 |
QEMUOptionParameter *options; |
402 |
int ret;
|
403 |
Error *err; |
404 |
} CreateCo; |
405 |
|
406 |
static void coroutine_fn bdrv_create_co_entry(void *opaque) |
407 |
{ |
408 |
Error *local_err = NULL;
|
409 |
int ret;
|
410 |
|
411 |
CreateCo *cco = opaque; |
412 |
assert(cco->drv); |
413 |
|
414 |
ret = cco->drv->bdrv_create(cco->filename, cco->options, &local_err); |
415 |
if (error_is_set(&local_err)) {
|
416 |
error_propagate(&cco->err, local_err); |
417 |
} |
418 |
cco->ret = ret; |
419 |
} |
420 |
|
421 |
int bdrv_create(BlockDriver *drv, const char* filename, |
422 |
QEMUOptionParameter *options, Error **errp) |
423 |
{ |
424 |
int ret;
|
425 |
|
426 |
Coroutine *co; |
427 |
CreateCo cco = { |
428 |
.drv = drv, |
429 |
.filename = g_strdup(filename), |
430 |
.options = options, |
431 |
.ret = NOT_DONE, |
432 |
.err = NULL,
|
433 |
}; |
434 |
|
435 |
if (!drv->bdrv_create) {
|
436 |
error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
|
437 |
ret = -ENOTSUP; |
438 |
goto out;
|
439 |
} |
440 |
|
441 |
if (qemu_in_coroutine()) {
|
442 |
/* Fast-path if already in coroutine context */
|
443 |
bdrv_create_co_entry(&cco); |
444 |
} else {
|
445 |
co = qemu_coroutine_create(bdrv_create_co_entry); |
446 |
qemu_coroutine_enter(co, &cco); |
447 |
while (cco.ret == NOT_DONE) {
|
448 |
qemu_aio_wait(); |
449 |
} |
450 |
} |
451 |
|
452 |
ret = cco.ret; |
453 |
if (ret < 0) { |
454 |
if (error_is_set(&cco.err)) {
|
455 |
error_propagate(errp, cco.err); |
456 |
} else {
|
457 |
error_setg_errno(errp, -ret, "Could not create image");
|
458 |
} |
459 |
} |
460 |
|
461 |
out:
|
462 |
g_free(cco.filename); |
463 |
return ret;
|
464 |
} |
465 |
|
466 |
int bdrv_create_file(const char* filename, QEMUOptionParameter *options, |
467 |
Error **errp) |
468 |
{ |
469 |
BlockDriver *drv; |
470 |
Error *local_err = NULL;
|
471 |
int ret;
|
472 |
|
473 |
drv = bdrv_find_protocol(filename, true);
|
474 |
if (drv == NULL) { |
475 |
error_setg(errp, "Could not find protocol for file '%s'", filename);
|
476 |
return -ENOENT;
|
477 |
} |
478 |
|
479 |
ret = bdrv_create(drv, filename, options, &local_err); |
480 |
if (error_is_set(&local_err)) {
|
481 |
error_propagate(errp, local_err); |
482 |
} |
483 |
return ret;
|
484 |
} |
485 |
|
486 |
/*
|
487 |
* Create a uniquely-named empty temporary file.
|
488 |
* Return 0 upon success, otherwise a negative errno value.
|
489 |
*/
|
490 |
int get_tmp_filename(char *filename, int size) |
491 |
{ |
492 |
#ifdef _WIN32
|
493 |
char temp_dir[MAX_PATH];
|
494 |
/* GetTempFileName requires that its output buffer (4th param)
|
495 |
have length MAX_PATH or greater. */
|
496 |
assert(size >= MAX_PATH); |
497 |
return (GetTempPath(MAX_PATH, temp_dir)
|
498 |
&& GetTempFileName(temp_dir, "qem", 0, filename) |
499 |
? 0 : -GetLastError());
|
500 |
#else
|
501 |
int fd;
|
502 |
const char *tmpdir; |
503 |
tmpdir = getenv("TMPDIR");
|
504 |
if (!tmpdir)
|
505 |
tmpdir = "/tmp";
|
506 |
if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { |
507 |
return -EOVERFLOW;
|
508 |
} |
509 |
fd = mkstemp(filename); |
510 |
if (fd < 0) { |
511 |
return -errno;
|
512 |
} |
513 |
if (close(fd) != 0) { |
514 |
unlink(filename); |
515 |
return -errno;
|
516 |
} |
517 |
return 0; |
518 |
#endif
|
519 |
} |
520 |
|
521 |
/*
|
522 |
* Detect host devices. By convention, /dev/cdrom[N] is always
|
523 |
* recognized as a host CDROM.
|
524 |
*/
|
525 |
static BlockDriver *find_hdev_driver(const char *filename) |
526 |
{ |
527 |
int score_max = 0, score; |
528 |
BlockDriver *drv = NULL, *d;
|
529 |
|
530 |
QLIST_FOREACH(d, &bdrv_drivers, list) { |
531 |
if (d->bdrv_probe_device) {
|
532 |
score = d->bdrv_probe_device(filename); |
533 |
if (score > score_max) {
|
534 |
score_max = score; |
535 |
drv = d; |
536 |
} |
537 |
} |
538 |
} |
539 |
|
540 |
return drv;
|
541 |
} |
542 |
|
543 |
BlockDriver *bdrv_find_protocol(const char *filename, |
544 |
bool allow_protocol_prefix)
|
545 |
{ |
546 |
BlockDriver *drv1; |
547 |
char protocol[128]; |
548 |
int len;
|
549 |
const char *p; |
550 |
|
551 |
/* TODO Drivers without bdrv_file_open must be specified explicitly */
|
552 |
|
553 |
/*
|
554 |
* XXX(hch): we really should not let host device detection
|
555 |
* override an explicit protocol specification, but moving this
|
556 |
* later breaks access to device names with colons in them.
|
557 |
* Thanks to the brain-dead persistent naming schemes on udev-
|
558 |
* based Linux systems those actually are quite common.
|
559 |
*/
|
560 |
drv1 = find_hdev_driver(filename); |
561 |
if (drv1) {
|
562 |
return drv1;
|
563 |
} |
564 |
|
565 |
if (!path_has_protocol(filename) || !allow_protocol_prefix) {
|
566 |
return bdrv_find_format("file"); |
567 |
} |
568 |
|
569 |
p = strchr(filename, ':');
|
570 |
assert(p != NULL);
|
571 |
len = p - filename; |
572 |
if (len > sizeof(protocol) - 1) |
573 |
len = sizeof(protocol) - 1; |
574 |
memcpy(protocol, filename, len); |
575 |
protocol[len] = '\0';
|
576 |
QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
577 |
if (drv1->protocol_name &&
|
578 |
!strcmp(drv1->protocol_name, protocol)) { |
579 |
return drv1;
|
580 |
} |
581 |
} |
582 |
return NULL; |
583 |
} |
584 |
|
585 |
static int find_image_format(BlockDriverState *bs, const char *filename, |
586 |
BlockDriver **pdrv, Error **errp) |
587 |
{ |
588 |
int score, score_max;
|
589 |
BlockDriver *drv1, *drv; |
590 |
uint8_t buf[2048];
|
591 |
int ret = 0; |
592 |
|
593 |
/* Return the raw BlockDriver * to scsi-generic devices or empty drives */
|
594 |
if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { |
595 |
drv = bdrv_find_format("raw");
|
596 |
if (!drv) {
|
597 |
error_setg(errp, "Could not find raw image format");
|
598 |
ret = -ENOENT; |
599 |
} |
600 |
*pdrv = drv; |
601 |
return ret;
|
602 |
} |
603 |
|
604 |
ret = bdrv_pread(bs, 0, buf, sizeof(buf)); |
605 |
if (ret < 0) { |
606 |
error_setg_errno(errp, -ret, "Could not read image for determining its "
|
607 |
"format");
|
608 |
*pdrv = NULL;
|
609 |
return ret;
|
610 |
} |
611 |
|
612 |
score_max = 0;
|
613 |
drv = NULL;
|
614 |
QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
615 |
if (drv1->bdrv_probe) {
|
616 |
score = drv1->bdrv_probe(buf, ret, filename); |
617 |
if (score > score_max) {
|
618 |
score_max = score; |
619 |
drv = drv1; |
620 |
} |
621 |
} |
622 |
} |
623 |
if (!drv) {
|
624 |
error_setg(errp, "Could not determine image format: No compatible "
|
625 |
"driver found");
|
626 |
ret = -ENOENT; |
627 |
} |
628 |
*pdrv = drv; |
629 |
return ret;
|
630 |
} |
631 |
|
632 |
/**
|
633 |
* Set the current 'total_sectors' value
|
634 |
*/
|
635 |
static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) |
636 |
{ |
637 |
BlockDriver *drv = bs->drv; |
638 |
|
639 |
/* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
|
640 |
if (bs->sg)
|
641 |
return 0; |
642 |
|
643 |
/* query actual device if possible, otherwise just trust the hint */
|
644 |
if (drv->bdrv_getlength) {
|
645 |
int64_t length = drv->bdrv_getlength(bs); |
646 |
if (length < 0) { |
647 |
return length;
|
648 |
} |
649 |
hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); |
650 |
} |
651 |
|
652 |
bs->total_sectors = hint; |
653 |
return 0; |
654 |
} |
655 |
|
656 |
/**
|
657 |
* Set open flags for a given discard mode
|
658 |
*
|
659 |
* Return 0 on success, -1 if the discard mode was invalid.
|
660 |
*/
|
661 |
int bdrv_parse_discard_flags(const char *mode, int *flags) |
662 |
{ |
663 |
*flags &= ~BDRV_O_UNMAP; |
664 |
|
665 |
if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { |
666 |
/* do nothing */
|
667 |
} else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { |
668 |
*flags |= BDRV_O_UNMAP; |
669 |
} else {
|
670 |
return -1; |
671 |
} |
672 |
|
673 |
return 0; |
674 |
} |
675 |
|
676 |
/**
|
677 |
* Set open flags for a given cache mode
|
678 |
*
|
679 |
* Return 0 on success, -1 if the cache mode was invalid.
|
680 |
*/
|
681 |
int bdrv_parse_cache_flags(const char *mode, int *flags) |
682 |
{ |
683 |
*flags &= ~BDRV_O_CACHE_MASK; |
684 |
|
685 |
if (!strcmp(mode, "off") || !strcmp(mode, "none")) { |
686 |
*flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; |
687 |
} else if (!strcmp(mode, "directsync")) { |
688 |
*flags |= BDRV_O_NOCACHE; |
689 |
} else if (!strcmp(mode, "writeback")) { |
690 |
*flags |= BDRV_O_CACHE_WB; |
691 |
} else if (!strcmp(mode, "unsafe")) { |
692 |
*flags |= BDRV_O_CACHE_WB; |
693 |
*flags |= BDRV_O_NO_FLUSH; |
694 |
} else if (!strcmp(mode, "writethrough")) { |
695 |
/* this is the default */
|
696 |
} else {
|
697 |
return -1; |
698 |
} |
699 |
|
700 |
return 0; |
701 |
} |
702 |
|
703 |
/**
|
704 |
* The copy-on-read flag is actually a reference count so multiple users may
|
705 |
* use the feature without worrying about clobbering its previous state.
|
706 |
* Copy-on-read stays enabled until all users have called to disable it.
|
707 |
*/
|
708 |
void bdrv_enable_copy_on_read(BlockDriverState *bs)
|
709 |
{ |
710 |
bs->copy_on_read++; |
711 |
} |
712 |
|
713 |
void bdrv_disable_copy_on_read(BlockDriverState *bs)
|
714 |
{ |
715 |
assert(bs->copy_on_read > 0);
|
716 |
bs->copy_on_read--; |
717 |
} |
718 |
|
719 |
static int bdrv_open_flags(BlockDriverState *bs, int flags) |
720 |
{ |
721 |
int open_flags = flags | BDRV_O_CACHE_WB;
|
722 |
|
723 |
/*
|
724 |
* Clear flags that are internal to the block layer before opening the
|
725 |
* image.
|
726 |
*/
|
727 |
open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
728 |
|
729 |
/*
|
730 |
* Snapshots should be writable.
|
731 |
*/
|
732 |
if (bs->is_temporary) {
|
733 |
open_flags |= BDRV_O_RDWR; |
734 |
} |
735 |
|
736 |
return open_flags;
|
737 |
} |
738 |
|
739 |
static int bdrv_assign_node_name(BlockDriverState *bs, |
740 |
const char *node_name, |
741 |
Error **errp) |
742 |
{ |
743 |
if (!node_name) {
|
744 |
return 0; |
745 |
} |
746 |
|
747 |
/* empty string node name is invalid */
|
748 |
if (node_name[0] == '\0') { |
749 |
error_setg(errp, "Empty node name");
|
750 |
return -EINVAL;
|
751 |
} |
752 |
|
753 |
/* takes care of avoiding duplicates node names */
|
754 |
if (bdrv_find_node(node_name)) {
|
755 |
error_setg(errp, "Duplicate node name");
|
756 |
return -EINVAL;
|
757 |
} |
758 |
|
759 |
/* copy node name into the bs and insert it into the graph list */
|
760 |
pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
|
761 |
QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); |
762 |
|
763 |
return 0; |
764 |
} |
765 |
|
766 |
/*
|
767 |
* Common part for opening disk images and files
|
768 |
*
|
769 |
* Removes all processed options from *options.
|
770 |
*/
|
771 |
static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, |
772 |
QDict *options, int flags, BlockDriver *drv, Error **errp)
|
773 |
{ |
774 |
int ret, open_flags;
|
775 |
const char *filename; |
776 |
const char *node_name = NULL; |
777 |
Error *local_err = NULL;
|
778 |
|
779 |
assert(drv != NULL);
|
780 |
assert(bs->file == NULL);
|
781 |
assert(options != NULL && bs->options != options);
|
782 |
|
783 |
if (file != NULL) { |
784 |
filename = file->filename; |
785 |
} else {
|
786 |
filename = qdict_get_try_str(options, "filename");
|
787 |
} |
788 |
|
789 |
trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
|
790 |
|
791 |
node_name = qdict_get_try_str(options, "node-name");
|
792 |
ret = bdrv_assign_node_name(bs, node_name, errp); |
793 |
if (ret < 0) { |
794 |
return ret;
|
795 |
} |
796 |
qdict_del(options, "node-name");
|
797 |
|
798 |
/* bdrv_open() with directly using a protocol as drv. This layer is already
|
799 |
* opened, so assign it to bs (while file becomes a closed BlockDriverState)
|
800 |
* and return immediately. */
|
801 |
if (file != NULL && drv->bdrv_file_open) { |
802 |
bdrv_swap(file, bs); |
803 |
return 0; |
804 |
} |
805 |
|
806 |
bs->open_flags = flags; |
807 |
bs->buffer_alignment = 512;
|
808 |
bs->zero_beyond_eof = true;
|
809 |
open_flags = bdrv_open_flags(bs, flags); |
810 |
bs->read_only = !(open_flags & BDRV_O_RDWR); |
811 |
|
812 |
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
|
813 |
error_setg(errp, |
814 |
!bs->read_only && bdrv_is_whitelisted(drv, true)
|
815 |
? "Driver '%s' can only be used for read-only devices"
|
816 |
: "Driver '%s' is not whitelisted",
|
817 |
drv->format_name); |
818 |
return -ENOTSUP;
|
819 |
} |
820 |
|
821 |
assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ |
822 |
if (flags & BDRV_O_COPY_ON_READ) {
|
823 |
if (!bs->read_only) {
|
824 |
bdrv_enable_copy_on_read(bs); |
825 |
} else {
|
826 |
error_setg(errp, "Can't use copy-on-read on read-only device");
|
827 |
return -EINVAL;
|
828 |
} |
829 |
} |
830 |
|
831 |
if (filename != NULL) { |
832 |
pstrcpy(bs->filename, sizeof(bs->filename), filename);
|
833 |
} else {
|
834 |
bs->filename[0] = '\0'; |
835 |
} |
836 |
|
837 |
bs->drv = drv; |
838 |
bs->opaque = g_malloc0(drv->instance_size); |
839 |
|
840 |
bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); |
841 |
|
842 |
/* Open the image, either directly or using a protocol */
|
843 |
if (drv->bdrv_file_open) {
|
844 |
assert(file == NULL);
|
845 |
assert(!drv->bdrv_needs_filename || filename != NULL);
|
846 |
ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); |
847 |
} else {
|
848 |
if (file == NULL) { |
849 |
error_setg(errp, "Can't use '%s' as a block driver for the "
|
850 |
"protocol level", drv->format_name);
|
851 |
ret = -EINVAL; |
852 |
goto free_and_fail;
|
853 |
} |
854 |
bs->file = file; |
855 |
ret = drv->bdrv_open(bs, options, open_flags, &local_err); |
856 |
} |
857 |
|
858 |
if (ret < 0) { |
859 |
if (error_is_set(&local_err)) {
|
860 |
error_propagate(errp, local_err); |
861 |
} else if (bs->filename[0]) { |
862 |
error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
|
863 |
} else {
|
864 |
error_setg_errno(errp, -ret, "Could not open image");
|
865 |
} |
866 |
goto free_and_fail;
|
867 |
} |
868 |
|
869 |
ret = refresh_total_sectors(bs, bs->total_sectors); |
870 |
if (ret < 0) { |
871 |
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
872 |
goto free_and_fail;
|
873 |
} |
874 |
|
875 |
#ifndef _WIN32
|
876 |
if (bs->is_temporary) {
|
877 |
assert(bs->filename[0] != '\0'); |
878 |
unlink(bs->filename); |
879 |
} |
880 |
#endif
|
881 |
return 0; |
882 |
|
883 |
free_and_fail:
|
884 |
bs->file = NULL;
|
885 |
g_free(bs->opaque); |
886 |
bs->opaque = NULL;
|
887 |
bs->drv = NULL;
|
888 |
return ret;
|
889 |
} |
890 |
|
891 |
/*
|
892 |
* Opens a file using a protocol (file, host_device, nbd, ...)
|
893 |
*
|
894 |
* options is a QDict of options to pass to the block drivers, or NULL for an
|
895 |
* empty set of options. The reference to the QDict belongs to the block layer
|
896 |
* after the call (even on failure), so if the caller intends to reuse the
|
897 |
* dictionary, it needs to use QINCREF() before calling bdrv_file_open.
|
898 |
*/
|
899 |
int bdrv_file_open(BlockDriverState **pbs, const char *filename, |
900 |
const char *reference, QDict *options, int flags, |
901 |
Error **errp) |
902 |
{ |
903 |
BlockDriverState *bs = NULL;
|
904 |
BlockDriver *drv; |
905 |
const char *drvname; |
906 |
bool allow_protocol_prefix = false; |
907 |
Error *local_err = NULL;
|
908 |
int ret;
|
909 |
|
910 |
/* NULL means an empty set of options */
|
911 |
if (options == NULL) { |
912 |
options = qdict_new(); |
913 |
} |
914 |
|
915 |
if (reference) {
|
916 |
if (filename || qdict_size(options)) {
|
917 |
error_setg(errp, "Cannot reference an existing block device with "
|
918 |
"additional options or a new filename");
|
919 |
return -EINVAL;
|
920 |
} |
921 |
QDECREF(options); |
922 |
|
923 |
bs = bdrv_find(reference); |
924 |
if (!bs) {
|
925 |
error_setg(errp, "Cannot find block device '%s'", reference);
|
926 |
return -ENODEV;
|
927 |
} |
928 |
bdrv_ref(bs); |
929 |
*pbs = bs; |
930 |
return 0; |
931 |
} |
932 |
|
933 |
bs = bdrv_new("");
|
934 |
bs->options = options; |
935 |
options = qdict_clone_shallow(options); |
936 |
|
937 |
/* Fetch the file name from the options QDict if necessary */
|
938 |
if (!filename) {
|
939 |
filename = qdict_get_try_str(options, "filename");
|
940 |
} else if (filename && !qdict_haskey(options, "filename")) { |
941 |
qdict_put(options, "filename", qstring_from_str(filename));
|
942 |
allow_protocol_prefix = true;
|
943 |
} else {
|
944 |
error_setg(errp, "Can't specify 'file' and 'filename' options at the "
|
945 |
"same time");
|
946 |
ret = -EINVAL; |
947 |
goto fail;
|
948 |
} |
949 |
|
950 |
/* Find the right block driver */
|
951 |
drvname = qdict_get_try_str(options, "driver");
|
952 |
if (drvname) {
|
953 |
drv = bdrv_find_format(drvname); |
954 |
if (!drv) {
|
955 |
error_setg(errp, "Unknown driver '%s'", drvname);
|
956 |
} |
957 |
qdict_del(options, "driver");
|
958 |
} else if (filename) { |
959 |
drv = bdrv_find_protocol(filename, allow_protocol_prefix); |
960 |
if (!drv) {
|
961 |
error_setg(errp, "Unknown protocol");
|
962 |
} |
963 |
} else {
|
964 |
error_setg(errp, "Must specify either driver or file");
|
965 |
drv = NULL;
|
966 |
} |
967 |
|
968 |
if (!drv) {
|
969 |
/* errp has been set already */
|
970 |
ret = -ENOENT; |
971 |
goto fail;
|
972 |
} |
973 |
|
974 |
/* Parse the filename and open it */
|
975 |
if (drv->bdrv_parse_filename && filename) {
|
976 |
drv->bdrv_parse_filename(filename, options, &local_err); |
977 |
if (error_is_set(&local_err)) {
|
978 |
error_propagate(errp, local_err); |
979 |
ret = -EINVAL; |
980 |
goto fail;
|
981 |
} |
982 |
qdict_del(options, "filename");
|
983 |
} else if (drv->bdrv_needs_filename && !filename) { |
984 |
error_setg(errp, "The '%s' block driver requires a file name",
|
985 |
drv->format_name); |
986 |
ret = -EINVAL; |
987 |
goto fail;
|
988 |
} |
989 |
|
990 |
if (!drv->bdrv_file_open) {
|
991 |
ret = bdrv_open(bs, filename, options, flags, drv, &local_err); |
992 |
options = NULL;
|
993 |
} else {
|
994 |
ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
|
995 |
} |
996 |
if (ret < 0) { |
997 |
error_propagate(errp, local_err); |
998 |
goto fail;
|
999 |
} |
1000 |
|
1001 |
/* Check if any unknown options were used */
|
1002 |
if (options && (qdict_size(options) != 0)) { |
1003 |
const QDictEntry *entry = qdict_first(options);
|
1004 |
error_setg(errp, "Block protocol '%s' doesn't support the option '%s'",
|
1005 |
drv->format_name, entry->key); |
1006 |
ret = -EINVAL; |
1007 |
goto fail;
|
1008 |
} |
1009 |
QDECREF(options); |
1010 |
|
1011 |
bs->growable = 1;
|
1012 |
*pbs = bs; |
1013 |
return 0; |
1014 |
|
1015 |
fail:
|
1016 |
QDECREF(options); |
1017 |
if (!bs->drv) {
|
1018 |
QDECREF(bs->options); |
1019 |
} |
1020 |
bdrv_unref(bs); |
1021 |
return ret;
|
1022 |
} |
1023 |
|
1024 |
/*
|
1025 |
* Opens the backing file for a BlockDriverState if not yet open
|
1026 |
*
|
1027 |
* options is a QDict of options to pass to the block drivers, or NULL for an
|
1028 |
* empty set of options. The reference to the QDict is transferred to this
|
1029 |
* function (even on failure), so if the caller intends to reuse the dictionary,
|
1030 |
* it needs to use QINCREF() before calling bdrv_file_open.
|
1031 |
*/
|
1032 |
int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
|
1033 |
{ |
1034 |
char backing_filename[PATH_MAX];
|
1035 |
int back_flags, ret;
|
1036 |
BlockDriver *back_drv = NULL;
|
1037 |
Error *local_err = NULL;
|
1038 |
|
1039 |
if (bs->backing_hd != NULL) { |
1040 |
QDECREF(options); |
1041 |
return 0; |
1042 |
} |
1043 |
|
1044 |
/* NULL means an empty set of options */
|
1045 |
if (options == NULL) { |
1046 |
options = qdict_new(); |
1047 |
} |
1048 |
|
1049 |
bs->open_flags &= ~BDRV_O_NO_BACKING; |
1050 |
if (qdict_haskey(options, "file.filename")) { |
1051 |
backing_filename[0] = '\0'; |
1052 |
} else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { |
1053 |
QDECREF(options); |
1054 |
return 0; |
1055 |
} else {
|
1056 |
bdrv_get_full_backing_filename(bs, backing_filename, |
1057 |
sizeof(backing_filename));
|
1058 |
} |
1059 |
|
1060 |
bs->backing_hd = bdrv_new("");
|
1061 |
|
1062 |
if (bs->backing_format[0] != '\0') { |
1063 |
back_drv = bdrv_find_format(bs->backing_format); |
1064 |
} |
1065 |
|
1066 |
/* backing files always opened read-only */
|
1067 |
back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | |
1068 |
BDRV_O_COPY_ON_READ); |
1069 |
|
1070 |
ret = bdrv_open(bs->backing_hd, |
1071 |
*backing_filename ? backing_filename : NULL, options,
|
1072 |
back_flags, back_drv, &local_err); |
1073 |
if (ret < 0) { |
1074 |
bdrv_unref(bs->backing_hd); |
1075 |
bs->backing_hd = NULL;
|
1076 |
bs->open_flags |= BDRV_O_NO_BACKING; |
1077 |
error_setg(errp, "Could not open backing file: %s",
|
1078 |
error_get_pretty(local_err)); |
1079 |
error_free(local_err); |
1080 |
return ret;
|
1081 |
} |
1082 |
|
1083 |
if (bs->backing_hd->file) {
|
1084 |
pstrcpy(bs->backing_file, sizeof(bs->backing_file),
|
1085 |
bs->backing_hd->file->filename); |
1086 |
} |
1087 |
|
1088 |
return 0; |
1089 |
} |
1090 |
|
1091 |
/*
|
1092 |
* Opens a disk image whose options are given as BlockdevRef in another block
|
1093 |
* device's options.
|
1094 |
*
|
1095 |
* If force_raw is true, bdrv_file_open() will be used, thereby preventing any
|
1096 |
* image format auto-detection. If it is false and a filename is given,
|
1097 |
* bdrv_open() will be used for auto-detection.
|
1098 |
*
|
1099 |
* If allow_none is true, no image will be opened if filename is false and no
|
1100 |
* BlockdevRef is given. *pbs will remain unchanged and 0 will be returned.
|
1101 |
*
|
1102 |
* bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
|
1103 |
* That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
|
1104 |
* itself, all options starting with "${bdref_key}." are considered part of the
|
1105 |
* BlockdevRef.
|
1106 |
*
|
1107 |
* The BlockdevRef will be removed from the options QDict.
|
1108 |
*/
|
1109 |
int bdrv_open_image(BlockDriverState **pbs, const char *filename, |
1110 |
QDict *options, const char *bdref_key, int flags, |
1111 |
bool force_raw, bool allow_none, Error **errp) |
1112 |
{ |
1113 |
QDict *image_options; |
1114 |
int ret;
|
1115 |
char *bdref_key_dot;
|
1116 |
const char *reference; |
1117 |
|
1118 |
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
|
1119 |
qdict_extract_subqdict(options, &image_options, bdref_key_dot); |
1120 |
g_free(bdref_key_dot); |
1121 |
|
1122 |
reference = qdict_get_try_str(options, bdref_key); |
1123 |
if (!filename && !reference && !qdict_size(image_options)) {
|
1124 |
if (allow_none) {
|
1125 |
ret = 0;
|
1126 |
} else {
|
1127 |
error_setg(errp, "A block device must be specified for \"%s\"",
|
1128 |
bdref_key); |
1129 |
ret = -EINVAL; |
1130 |
} |
1131 |
goto done;
|
1132 |
} |
1133 |
|
1134 |
if (filename && !force_raw) {
|
1135 |
/* If a filename is given and the block driver should be detected
|
1136 |
automatically (instead of using none), use bdrv_open() in order to do
|
1137 |
that auto-detection. */
|
1138 |
BlockDriverState *bs; |
1139 |
|
1140 |
if (reference) {
|
1141 |
error_setg(errp, "Cannot reference an existing block device while "
|
1142 |
"giving a filename");
|
1143 |
ret = -EINVAL; |
1144 |
goto done;
|
1145 |
} |
1146 |
|
1147 |
bs = bdrv_new("");
|
1148 |
ret = bdrv_open(bs, filename, image_options, flags, NULL, errp);
|
1149 |
if (ret < 0) { |
1150 |
bdrv_unref(bs); |
1151 |
} else {
|
1152 |
*pbs = bs; |
1153 |
} |
1154 |
} else {
|
1155 |
ret = bdrv_file_open(pbs, filename, reference, image_options, flags, |
1156 |
errp); |
1157 |
} |
1158 |
|
1159 |
done:
|
1160 |
qdict_del(options, bdref_key); |
1161 |
return ret;
|
1162 |
} |
1163 |
|
1164 |
/*
|
1165 |
* Opens a disk image (raw, qcow2, vmdk, ...)
|
1166 |
*
|
1167 |
* options is a QDict of options to pass to the block drivers, or NULL for an
|
1168 |
* empty set of options. The reference to the QDict belongs to the block layer
|
1169 |
* after the call (even on failure), so if the caller intends to reuse the
|
1170 |
* dictionary, it needs to use QINCREF() before calling bdrv_open.
|
1171 |
*/
|
1172 |
int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, |
1173 |
int flags, BlockDriver *drv, Error **errp)
|
1174 |
{ |
1175 |
int ret;
|
1176 |
/* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
|
1177 |
char tmp_filename[PATH_MAX + 1]; |
1178 |
BlockDriverState *file = NULL;
|
1179 |
const char *drvname; |
1180 |
Error *local_err = NULL;
|
1181 |
|
1182 |
/* NULL means an empty set of options */
|
1183 |
if (options == NULL) { |
1184 |
options = qdict_new(); |
1185 |
} |
1186 |
|
1187 |
bs->options = options; |
1188 |
options = qdict_clone_shallow(options); |
1189 |
|
1190 |
/* For snapshot=on, create a temporary qcow2 overlay */
|
1191 |
if (flags & BDRV_O_SNAPSHOT) {
|
1192 |
BlockDriverState *bs1; |
1193 |
int64_t total_size; |
1194 |
BlockDriver *bdrv_qcow2; |
1195 |
QEMUOptionParameter *create_options; |
1196 |
QDict *snapshot_options; |
1197 |
|
1198 |
/* if snapshot, we create a temporary backing file and open it
|
1199 |
instead of opening 'filename' directly */
|
1200 |
|
1201 |
/* Get the required size from the image */
|
1202 |
bs1 = bdrv_new("");
|
1203 |
QINCREF(options); |
1204 |
ret = bdrv_open(bs1, filename, options, BDRV_O_NO_BACKING, |
1205 |
drv, &local_err); |
1206 |
if (ret < 0) { |
1207 |
bdrv_unref(bs1); |
1208 |
goto fail;
|
1209 |
} |
1210 |
total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK; |
1211 |
|
1212 |
bdrv_unref(bs1); |
1213 |
|
1214 |
/* Create the temporary image */
|
1215 |
ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename));
|
1216 |
if (ret < 0) { |
1217 |
error_setg_errno(errp, -ret, "Could not get temporary filename");
|
1218 |
goto fail;
|
1219 |
} |
1220 |
|
1221 |
bdrv_qcow2 = bdrv_find_format("qcow2");
|
1222 |
create_options = parse_option_parameters("", bdrv_qcow2->create_options,
|
1223 |
NULL);
|
1224 |
|
1225 |
set_option_parameter_int(create_options, BLOCK_OPT_SIZE, total_size); |
1226 |
|
1227 |
ret = bdrv_create(bdrv_qcow2, tmp_filename, create_options, &local_err); |
1228 |
free_option_parameters(create_options); |
1229 |
if (ret < 0) { |
1230 |
error_setg_errno(errp, -ret, "Could not create temporary overlay "
|
1231 |
"'%s': %s", tmp_filename,
|
1232 |
error_get_pretty(local_err)); |
1233 |
error_free(local_err); |
1234 |
local_err = NULL;
|
1235 |
goto fail;
|
1236 |
} |
1237 |
|
1238 |
/* Prepare a new options QDict for the temporary file, where user
|
1239 |
* options refer to the backing file */
|
1240 |
if (filename) {
|
1241 |
qdict_put(options, "file.filename", qstring_from_str(filename));
|
1242 |
} |
1243 |
if (drv) {
|
1244 |
qdict_put(options, "driver", qstring_from_str(drv->format_name));
|
1245 |
} |
1246 |
|
1247 |
snapshot_options = qdict_new(); |
1248 |
qdict_put(snapshot_options, "backing", options);
|
1249 |
qdict_flatten(snapshot_options); |
1250 |
|
1251 |
bs->options = snapshot_options; |
1252 |
options = qdict_clone_shallow(bs->options); |
1253 |
|
1254 |
filename = tmp_filename; |
1255 |
drv = bdrv_qcow2; |
1256 |
bs->is_temporary = 1;
|
1257 |
} |
1258 |
|
1259 |
/* Open image file without format layer */
|
1260 |
if (flags & BDRV_O_RDWR) {
|
1261 |
flags |= BDRV_O_ALLOW_RDWR; |
1262 |
} |
1263 |
|
1264 |
ret = bdrv_open_image(&file, filename, options, "file",
|
1265 |
bdrv_open_flags(bs, flags | BDRV_O_UNMAP), true, true, |
1266 |
&local_err); |
1267 |
if (ret < 0) { |
1268 |
goto fail;
|
1269 |
} |
1270 |
|
1271 |
/* Find the right image format driver */
|
1272 |
drvname = qdict_get_try_str(options, "driver");
|
1273 |
if (drvname) {
|
1274 |
drv = bdrv_find_format(drvname); |
1275 |
qdict_del(options, "driver");
|
1276 |
if (!drv) {
|
1277 |
error_setg(errp, "Invalid driver: '%s'", drvname);
|
1278 |
ret = -EINVAL; |
1279 |
goto unlink_and_fail;
|
1280 |
} |
1281 |
} |
1282 |
|
1283 |
if (!drv) {
|
1284 |
if (file) {
|
1285 |
ret = find_image_format(file, filename, &drv, &local_err); |
1286 |
} else {
|
1287 |
error_setg(errp, "Must specify either driver or file");
|
1288 |
ret = -EINVAL; |
1289 |
goto unlink_and_fail;
|
1290 |
} |
1291 |
} |
1292 |
|
1293 |
if (!drv) {
|
1294 |
goto unlink_and_fail;
|
1295 |
} |
1296 |
|
1297 |
/* Open the image */
|
1298 |
ret = bdrv_open_common(bs, file, options, flags, drv, &local_err); |
1299 |
if (ret < 0) { |
1300 |
goto unlink_and_fail;
|
1301 |
} |
1302 |
|
1303 |
if (file && (bs->file != file)) {
|
1304 |
bdrv_unref(file); |
1305 |
file = NULL;
|
1306 |
} |
1307 |
|
1308 |
/* If there is a backing file, use it */
|
1309 |
if ((flags & BDRV_O_NO_BACKING) == 0) { |
1310 |
QDict *backing_options; |
1311 |
|
1312 |
qdict_extract_subqdict(options, &backing_options, "backing.");
|
1313 |
ret = bdrv_open_backing_file(bs, backing_options, &local_err); |
1314 |
if (ret < 0) { |
1315 |
goto close_and_fail;
|
1316 |
} |
1317 |
} |
1318 |
|
1319 |
/* Check if any unknown options were used */
|
1320 |
if (qdict_size(options) != 0) { |
1321 |
const QDictEntry *entry = qdict_first(options);
|
1322 |
error_setg(errp, "Block format '%s' used by device '%s' doesn't "
|
1323 |
"support the option '%s'", drv->format_name, bs->device_name,
|
1324 |
entry->key); |
1325 |
|
1326 |
ret = -EINVAL; |
1327 |
goto close_and_fail;
|
1328 |
} |
1329 |
QDECREF(options); |
1330 |
|
1331 |
if (!bdrv_key_required(bs)) {
|
1332 |
bdrv_dev_change_media_cb(bs, true);
|
1333 |
} |
1334 |
|
1335 |
return 0; |
1336 |
|
1337 |
unlink_and_fail:
|
1338 |
if (file != NULL) { |
1339 |
bdrv_unref(file); |
1340 |
} |
1341 |
if (bs->is_temporary) {
|
1342 |
unlink(filename); |
1343 |
} |
1344 |
fail:
|
1345 |
QDECREF(bs->options); |
1346 |
QDECREF(options); |
1347 |
bs->options = NULL;
|
1348 |
if (error_is_set(&local_err)) {
|
1349 |
error_propagate(errp, local_err); |
1350 |
} |
1351 |
return ret;
|
1352 |
|
1353 |
close_and_fail:
|
1354 |
bdrv_close(bs); |
1355 |
QDECREF(options); |
1356 |
if (error_is_set(&local_err)) {
|
1357 |
error_propagate(errp, local_err); |
1358 |
} |
1359 |
return ret;
|
1360 |
} |
1361 |
|
1362 |
typedef struct BlockReopenQueueEntry { |
1363 |
bool prepared;
|
1364 |
BDRVReopenState state; |
1365 |
QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; |
1366 |
} BlockReopenQueueEntry; |
1367 |
|
1368 |
/*
|
1369 |
* Adds a BlockDriverState to a simple queue for an atomic, transactional
|
1370 |
* reopen of multiple devices.
|
1371 |
*
|
1372 |
* bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
|
1373 |
* already performed, or alternatively may be NULL a new BlockReopenQueue will
|
1374 |
* be created and initialized. This newly created BlockReopenQueue should be
|
1375 |
* passed back in for subsequent calls that are intended to be of the same
|
1376 |
* atomic 'set'.
|
1377 |
*
|
1378 |
* bs is the BlockDriverState to add to the reopen queue.
|
1379 |
*
|
1380 |
* flags contains the open flags for the associated bs
|
1381 |
*
|
1382 |
* returns a pointer to bs_queue, which is either the newly allocated
|
1383 |
* bs_queue, or the existing bs_queue being used.
|
1384 |
*
|
1385 |
*/
|
1386 |
BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, |
1387 |
BlockDriverState *bs, int flags)
|
1388 |
{ |
1389 |
assert(bs != NULL);
|
1390 |
|
1391 |
BlockReopenQueueEntry *bs_entry; |
1392 |
if (bs_queue == NULL) { |
1393 |
bs_queue = g_new0(BlockReopenQueue, 1);
|
1394 |
QSIMPLEQ_INIT(bs_queue); |
1395 |
} |
1396 |
|
1397 |
if (bs->file) {
|
1398 |
bdrv_reopen_queue(bs_queue, bs->file, flags); |
1399 |
} |
1400 |
|
1401 |
bs_entry = g_new0(BlockReopenQueueEntry, 1);
|
1402 |
QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); |
1403 |
|
1404 |
bs_entry->state.bs = bs; |
1405 |
bs_entry->state.flags = flags; |
1406 |
|
1407 |
return bs_queue;
|
1408 |
} |
1409 |
|
1410 |
/*
|
1411 |
* Reopen multiple BlockDriverStates atomically & transactionally.
|
1412 |
*
|
1413 |
* The queue passed in (bs_queue) must have been built up previous
|
1414 |
* via bdrv_reopen_queue().
|
1415 |
*
|
1416 |
* Reopens all BDS specified in the queue, with the appropriate
|
1417 |
* flags. All devices are prepared for reopen, and failure of any
|
1418 |
* device will cause all device changes to be abandonded, and intermediate
|
1419 |
* data cleaned up.
|
1420 |
*
|
1421 |
* If all devices prepare successfully, then the changes are committed
|
1422 |
* to all devices.
|
1423 |
*
|
1424 |
*/
|
1425 |
int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
|
1426 |
{ |
1427 |
int ret = -1; |
1428 |
BlockReopenQueueEntry *bs_entry, *next; |
1429 |
Error *local_err = NULL;
|
1430 |
|
1431 |
assert(bs_queue != NULL);
|
1432 |
|
1433 |
bdrv_drain_all(); |
1434 |
|
1435 |
QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
1436 |
if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
|
1437 |
error_propagate(errp, local_err); |
1438 |
goto cleanup;
|
1439 |
} |
1440 |
bs_entry->prepared = true;
|
1441 |
} |
1442 |
|
1443 |
/* If we reach this point, we have success and just need to apply the
|
1444 |
* changes
|
1445 |
*/
|
1446 |
QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
1447 |
bdrv_reopen_commit(&bs_entry->state); |
1448 |
} |
1449 |
|
1450 |
ret = 0;
|
1451 |
|
1452 |
cleanup:
|
1453 |
QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { |
1454 |
if (ret && bs_entry->prepared) {
|
1455 |
bdrv_reopen_abort(&bs_entry->state); |
1456 |
} |
1457 |
g_free(bs_entry); |
1458 |
} |
1459 |
g_free(bs_queue); |
1460 |
return ret;
|
1461 |
} |
1462 |
|
1463 |
|
1464 |
/* Reopen a single BlockDriverState with the specified flags. */
|
1465 |
int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) |
1466 |
{ |
1467 |
int ret = -1; |
1468 |
Error *local_err = NULL;
|
1469 |
BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, bdrv_flags);
|
1470 |
|
1471 |
ret = bdrv_reopen_multiple(queue, &local_err); |
1472 |
if (local_err != NULL) { |
1473 |
error_propagate(errp, local_err); |
1474 |
} |
1475 |
return ret;
|
1476 |
} |
1477 |
|
1478 |
|
1479 |
/*
|
1480 |
* Prepares a BlockDriverState for reopen. All changes are staged in the
|
1481 |
* 'opaque' field of the BDRVReopenState, which is used and allocated by
|
1482 |
* the block driver layer .bdrv_reopen_prepare()
|
1483 |
*
|
1484 |
* bs is the BlockDriverState to reopen
|
1485 |
* flags are the new open flags
|
1486 |
* queue is the reopen queue
|
1487 |
*
|
1488 |
* Returns 0 on success, non-zero on error. On error errp will be set
|
1489 |
* as well.
|
1490 |
*
|
1491 |
* On failure, bdrv_reopen_abort() will be called to clean up any data.
|
1492 |
* It is the responsibility of the caller to then call the abort() or
|
1493 |
* commit() for any other BDS that have been left in a prepare() state
|
1494 |
*
|
1495 |
*/
|
1496 |
int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
|
1497 |
Error **errp) |
1498 |
{ |
1499 |
int ret = -1; |
1500 |
Error *local_err = NULL;
|
1501 |
BlockDriver *drv; |
1502 |
|
1503 |
assert(reopen_state != NULL);
|
1504 |
assert(reopen_state->bs->drv != NULL);
|
1505 |
drv = reopen_state->bs->drv; |
1506 |
|
1507 |
/* if we are to stay read-only, do not allow permission change
|
1508 |
* to r/w */
|
1509 |
if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) &&
|
1510 |
reopen_state->flags & BDRV_O_RDWR) { |
1511 |
error_set(errp, QERR_DEVICE_IS_READ_ONLY, |
1512 |
reopen_state->bs->device_name); |
1513 |
goto error;
|
1514 |
} |
1515 |
|
1516 |
|
1517 |
ret = bdrv_flush(reopen_state->bs); |
1518 |
if (ret) {
|
1519 |
error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive",
|
1520 |
strerror(-ret)); |
1521 |
goto error;
|
1522 |
} |
1523 |
|
1524 |
if (drv->bdrv_reopen_prepare) {
|
1525 |
ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); |
1526 |
if (ret) {
|
1527 |
if (local_err != NULL) { |
1528 |
error_propagate(errp, local_err); |
1529 |
} else {
|
1530 |
error_setg(errp, "failed while preparing to reopen image '%s'",
|
1531 |
reopen_state->bs->filename); |
1532 |
} |
1533 |
goto error;
|
1534 |
} |
1535 |
} else {
|
1536 |
/* It is currently mandatory to have a bdrv_reopen_prepare()
|
1537 |
* handler for each supported drv. */
|
1538 |
error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, |
1539 |
drv->format_name, reopen_state->bs->device_name, |
1540 |
"reopening of file");
|
1541 |
ret = -1;
|
1542 |
goto error;
|
1543 |
} |
1544 |
|
1545 |
ret = 0;
|
1546 |
|
1547 |
error:
|
1548 |
return ret;
|
1549 |
} |
1550 |
|
1551 |
/*
|
1552 |
* Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
|
1553 |
* makes them final by swapping the staging BlockDriverState contents into
|
1554 |
* the active BlockDriverState contents.
|
1555 |
*/
|
1556 |
void bdrv_reopen_commit(BDRVReopenState *reopen_state)
|
1557 |
{ |
1558 |
BlockDriver *drv; |
1559 |
|
1560 |
assert(reopen_state != NULL);
|
1561 |
drv = reopen_state->bs->drv; |
1562 |
assert(drv != NULL);
|
1563 |
|
1564 |
/* If there are any driver level actions to take */
|
1565 |
if (drv->bdrv_reopen_commit) {
|
1566 |
drv->bdrv_reopen_commit(reopen_state); |
1567 |
} |
1568 |
|
1569 |
/* set BDS specific flags now */
|
1570 |
reopen_state->bs->open_flags = reopen_state->flags; |
1571 |
reopen_state->bs->enable_write_cache = !!(reopen_state->flags & |
1572 |
BDRV_O_CACHE_WB); |
1573 |
reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); |
1574 |
} |
1575 |
|
1576 |
/*
|
1577 |
* Abort the reopen, and delete and free the staged changes in
|
1578 |
* reopen_state
|
1579 |
*/
|
1580 |
void bdrv_reopen_abort(BDRVReopenState *reopen_state)
|
1581 |
{ |
1582 |
BlockDriver *drv; |
1583 |
|
1584 |
assert(reopen_state != NULL);
|
1585 |
drv = reopen_state->bs->drv; |
1586 |
assert(drv != NULL);
|
1587 |
|
1588 |
if (drv->bdrv_reopen_abort) {
|
1589 |
drv->bdrv_reopen_abort(reopen_state); |
1590 |
} |
1591 |
} |
1592 |
|
1593 |
|
1594 |
void bdrv_close(BlockDriverState *bs)
|
1595 |
{ |
1596 |
if (bs->job) {
|
1597 |
block_job_cancel_sync(bs->job); |
1598 |
} |
1599 |
bdrv_drain_all(); /* complete I/O */
|
1600 |
bdrv_flush(bs); |
1601 |
bdrv_drain_all(); /* in case flush left pending I/O */
|
1602 |
notifier_list_notify(&bs->close_notifiers, bs); |
1603 |
|
1604 |
if (bs->drv) {
|
1605 |
if (bs->backing_hd) {
|
1606 |
bdrv_unref(bs->backing_hd); |
1607 |
bs->backing_hd = NULL;
|
1608 |
} |
1609 |
bs->drv->bdrv_close(bs); |
1610 |
g_free(bs->opaque); |
1611 |
#ifdef _WIN32
|
1612 |
if (bs->is_temporary) {
|
1613 |
unlink(bs->filename); |
1614 |
} |
1615 |
#endif
|
1616 |
bs->opaque = NULL;
|
1617 |
bs->drv = NULL;
|
1618 |
bs->copy_on_read = 0;
|
1619 |
bs->backing_file[0] = '\0'; |
1620 |
bs->backing_format[0] = '\0'; |
1621 |
bs->total_sectors = 0;
|
1622 |
bs->encrypted = 0;
|
1623 |
bs->valid_key = 0;
|
1624 |
bs->sg = 0;
|
1625 |
bs->growable = 0;
|
1626 |
bs->zero_beyond_eof = false;
|
1627 |
QDECREF(bs->options); |
1628 |
bs->options = NULL;
|
1629 |
|
1630 |
if (bs->file != NULL) { |
1631 |
bdrv_unref(bs->file); |
1632 |
bs->file = NULL;
|
1633 |
} |
1634 |
} |
1635 |
|
1636 |
bdrv_dev_change_media_cb(bs, false);
|
1637 |
|
1638 |
/*throttling disk I/O limits*/
|
1639 |
if (bs->io_limits_enabled) {
|
1640 |
bdrv_io_limits_disable(bs); |
1641 |
} |
1642 |
} |
1643 |
|
1644 |
void bdrv_close_all(void) |
1645 |
{ |
1646 |
BlockDriverState *bs; |
1647 |
|
1648 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
1649 |
bdrv_close(bs); |
1650 |
} |
1651 |
} |
1652 |
|
1653 |
/* Check if any requests are in-flight (including throttled requests) */
|
1654 |
static bool bdrv_requests_pending(BlockDriverState *bs) |
1655 |
{ |
1656 |
if (!QLIST_EMPTY(&bs->tracked_requests)) {
|
1657 |
return true; |
1658 |
} |
1659 |
if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) { |
1660 |
return true; |
1661 |
} |
1662 |
if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) { |
1663 |
return true; |
1664 |
} |
1665 |
if (bs->file && bdrv_requests_pending(bs->file)) {
|
1666 |
return true; |
1667 |
} |
1668 |
if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
|
1669 |
return true; |
1670 |
} |
1671 |
return false; |
1672 |
} |
1673 |
|
1674 |
static bool bdrv_requests_pending_all(void) |
1675 |
{ |
1676 |
BlockDriverState *bs; |
1677 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
1678 |
if (bdrv_requests_pending(bs)) {
|
1679 |
return true; |
1680 |
} |
1681 |
} |
1682 |
return false; |
1683 |
} |
1684 |
|
1685 |
/*
|
1686 |
* Wait for pending requests to complete across all BlockDriverStates
|
1687 |
*
|
1688 |
* This function does not flush data to disk, use bdrv_flush_all() for that
|
1689 |
* after calling this function.
|
1690 |
*
|
1691 |
* Note that completion of an asynchronous I/O operation can trigger any
|
1692 |
* number of other I/O operations on other devices---for example a coroutine
|
1693 |
* can be arbitrarily complex and a constant flow of I/O can come until the
|
1694 |
* coroutine is complete. Because of this, it is not possible to have a
|
1695 |
* function to drain a single device's I/O queue.
|
1696 |
*/
|
1697 |
void bdrv_drain_all(void) |
1698 |
{ |
1699 |
/* Always run first iteration so any pending completion BHs run */
|
1700 |
bool busy = true; |
1701 |
BlockDriverState *bs; |
1702 |
|
1703 |
while (busy) {
|
1704 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
1705 |
bdrv_start_throttled_reqs(bs); |
1706 |
} |
1707 |
|
1708 |
busy = bdrv_requests_pending_all(); |
1709 |
busy |= aio_poll(qemu_get_aio_context(), busy); |
1710 |
} |
1711 |
} |
1712 |
|
1713 |
/* make a BlockDriverState anonymous by removing from bdrv_state and
|
1714 |
* graph_bdrv_state list.
|
1715 |
Also, NULL terminate the device_name to prevent double remove */
|
1716 |
void bdrv_make_anon(BlockDriverState *bs)
|
1717 |
{ |
1718 |
if (bs->device_name[0] != '\0') { |
1719 |
QTAILQ_REMOVE(&bdrv_states, bs, device_list); |
1720 |
} |
1721 |
bs->device_name[0] = '\0'; |
1722 |
if (bs->node_name[0] != '\0') { |
1723 |
QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); |
1724 |
} |
1725 |
bs->node_name[0] = '\0'; |
1726 |
} |
1727 |
|
1728 |
static void bdrv_rebind(BlockDriverState *bs) |
1729 |
{ |
1730 |
if (bs->drv && bs->drv->bdrv_rebind) {
|
1731 |
bs->drv->bdrv_rebind(bs); |
1732 |
} |
1733 |
} |
1734 |
|
1735 |
static void bdrv_move_feature_fields(BlockDriverState *bs_dest, |
1736 |
BlockDriverState *bs_src) |
1737 |
{ |
1738 |
/* move some fields that need to stay attached to the device */
|
1739 |
bs_dest->open_flags = bs_src->open_flags; |
1740 |
|
1741 |
/* dev info */
|
1742 |
bs_dest->dev_ops = bs_src->dev_ops; |
1743 |
bs_dest->dev_opaque = bs_src->dev_opaque; |
1744 |
bs_dest->dev = bs_src->dev; |
1745 |
bs_dest->buffer_alignment = bs_src->buffer_alignment; |
1746 |
bs_dest->copy_on_read = bs_src->copy_on_read; |
1747 |
|
1748 |
bs_dest->enable_write_cache = bs_src->enable_write_cache; |
1749 |
|
1750 |
/* i/o throttled req */
|
1751 |
memcpy(&bs_dest->throttle_state, |
1752 |
&bs_src->throttle_state, |
1753 |
sizeof(ThrottleState));
|
1754 |
bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0]; |
1755 |
bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1]; |
1756 |
bs_dest->io_limits_enabled = bs_src->io_limits_enabled; |
1757 |
|
1758 |
/* r/w error */
|
1759 |
bs_dest->on_read_error = bs_src->on_read_error; |
1760 |
bs_dest->on_write_error = bs_src->on_write_error; |
1761 |
|
1762 |
/* i/o status */
|
1763 |
bs_dest->iostatus_enabled = bs_src->iostatus_enabled; |
1764 |
bs_dest->iostatus = bs_src->iostatus; |
1765 |
|
1766 |
/* dirty bitmap */
|
1767 |
bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps; |
1768 |
|
1769 |
/* reference count */
|
1770 |
bs_dest->refcnt = bs_src->refcnt; |
1771 |
|
1772 |
/* job */
|
1773 |
bs_dest->in_use = bs_src->in_use; |
1774 |
bs_dest->job = bs_src->job; |
1775 |
|
1776 |
/* keep the same entry in bdrv_states */
|
1777 |
pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name),
|
1778 |
bs_src->device_name); |
1779 |
bs_dest->device_list = bs_src->device_list; |
1780 |
|
1781 |
/* keep the same entry in graph_bdrv_states
|
1782 |
* We do want to swap name but don't want to swap linked list entries
|
1783 |
*/
|
1784 |
bs_dest->node_list = bs_src->node_list; |
1785 |
} |
1786 |
|
1787 |
/*
|
1788 |
* Swap bs contents for two image chains while they are live,
|
1789 |
* while keeping required fields on the BlockDriverState that is
|
1790 |
* actually attached to a device.
|
1791 |
*
|
1792 |
* This will modify the BlockDriverState fields, and swap contents
|
1793 |
* between bs_new and bs_old. Both bs_new and bs_old are modified.
|
1794 |
*
|
1795 |
* bs_new is required to be anonymous.
|
1796 |
*
|
1797 |
* This function does not create any image files.
|
1798 |
*/
|
1799 |
void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
|
1800 |
{ |
1801 |
BlockDriverState tmp; |
1802 |
|
1803 |
/* bs_new must be anonymous and shouldn't have anything fancy enabled */
|
1804 |
assert(bs_new->device_name[0] == '\0'); |
1805 |
assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); |
1806 |
assert(bs_new->job == NULL);
|
1807 |
assert(bs_new->dev == NULL);
|
1808 |
assert(bs_new->in_use == 0);
|
1809 |
assert(bs_new->io_limits_enabled == false);
|
1810 |
assert(!throttle_have_timer(&bs_new->throttle_state)); |
1811 |
|
1812 |
tmp = *bs_new; |
1813 |
*bs_new = *bs_old; |
1814 |
*bs_old = tmp; |
1815 |
|
1816 |
/* there are some fields that should not be swapped, move them back */
|
1817 |
bdrv_move_feature_fields(&tmp, bs_old); |
1818 |
bdrv_move_feature_fields(bs_old, bs_new); |
1819 |
bdrv_move_feature_fields(bs_new, &tmp); |
1820 |
|
1821 |
/* bs_new shouldn't be in bdrv_states even after the swap! */
|
1822 |
assert(bs_new->device_name[0] == '\0'); |
1823 |
|
1824 |
/* Check a few fields that should remain attached to the device */
|
1825 |
assert(bs_new->dev == NULL);
|
1826 |
assert(bs_new->job == NULL);
|
1827 |
assert(bs_new->in_use == 0);
|
1828 |
assert(bs_new->io_limits_enabled == false);
|
1829 |
assert(!throttle_have_timer(&bs_new->throttle_state)); |
1830 |
|
1831 |
bdrv_rebind(bs_new); |
1832 |
bdrv_rebind(bs_old); |
1833 |
} |
1834 |
|
1835 |
/*
|
1836 |
* Add new bs contents at the top of an image chain while the chain is
|
1837 |
* live, while keeping required fields on the top layer.
|
1838 |
*
|
1839 |
* This will modify the BlockDriverState fields, and swap contents
|
1840 |
* between bs_new and bs_top. Both bs_new and bs_top are modified.
|
1841 |
*
|
1842 |
* bs_new is required to be anonymous.
|
1843 |
*
|
1844 |
* This function does not create any image files.
|
1845 |
*/
|
1846 |
void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
|
1847 |
{ |
1848 |
bdrv_swap(bs_new, bs_top); |
1849 |
|
1850 |
/* The contents of 'tmp' will become bs_top, as we are
|
1851 |
* swapping bs_new and bs_top contents. */
|
1852 |
bs_top->backing_hd = bs_new; |
1853 |
bs_top->open_flags &= ~BDRV_O_NO_BACKING; |
1854 |
pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file),
|
1855 |
bs_new->filename); |
1856 |
pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format),
|
1857 |
bs_new->drv ? bs_new->drv->format_name : "");
|
1858 |
} |
1859 |
|
1860 |
static void bdrv_delete(BlockDriverState *bs) |
1861 |
{ |
1862 |
assert(!bs->dev); |
1863 |
assert(!bs->job); |
1864 |
assert(!bs->in_use); |
1865 |
assert(!bs->refcnt); |
1866 |
assert(QLIST_EMPTY(&bs->dirty_bitmaps)); |
1867 |
|
1868 |
bdrv_close(bs); |
1869 |
|
1870 |
/* remove from list, if necessary */
|
1871 |
bdrv_make_anon(bs); |
1872 |
|
1873 |
g_free(bs); |
1874 |
} |
1875 |
|
1876 |
int bdrv_attach_dev(BlockDriverState *bs, void *dev) |
1877 |
/* TODO change to DeviceState *dev when all users are qdevified */
|
1878 |
{ |
1879 |
if (bs->dev) {
|
1880 |
return -EBUSY;
|
1881 |
} |
1882 |
bs->dev = dev; |
1883 |
bdrv_iostatus_reset(bs); |
1884 |
return 0; |
1885 |
} |
1886 |
|
1887 |
/* TODO qdevified devices don't use this, remove when devices are qdevified */
|
1888 |
void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev) |
1889 |
{ |
1890 |
if (bdrv_attach_dev(bs, dev) < 0) { |
1891 |
abort(); |
1892 |
} |
1893 |
} |
1894 |
|
1895 |
void bdrv_detach_dev(BlockDriverState *bs, void *dev) |
1896 |
/* TODO change to DeviceState *dev when all users are qdevified */
|
1897 |
{ |
1898 |
assert(bs->dev == dev); |
1899 |
bs->dev = NULL;
|
1900 |
bs->dev_ops = NULL;
|
1901 |
bs->dev_opaque = NULL;
|
1902 |
bs->buffer_alignment = 512;
|
1903 |
} |
1904 |
|
1905 |
/* TODO change to return DeviceState * when all users are qdevified */
|
1906 |
void *bdrv_get_attached_dev(BlockDriverState *bs)
|
1907 |
{ |
1908 |
return bs->dev;
|
1909 |
} |
1910 |
|
1911 |
void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, |
1912 |
void *opaque)
|
1913 |
{ |
1914 |
bs->dev_ops = ops; |
1915 |
bs->dev_opaque = opaque; |
1916 |
} |
1917 |
|
1918 |
void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, |
1919 |
enum MonitorEvent ev,
|
1920 |
BlockErrorAction action, bool is_read)
|
1921 |
{ |
1922 |
QObject *data; |
1923 |
const char *action_str; |
1924 |
|
1925 |
switch (action) {
|
1926 |
case BDRV_ACTION_REPORT:
|
1927 |
action_str = "report";
|
1928 |
break;
|
1929 |
case BDRV_ACTION_IGNORE:
|
1930 |
action_str = "ignore";
|
1931 |
break;
|
1932 |
case BDRV_ACTION_STOP:
|
1933 |
action_str = "stop";
|
1934 |
break;
|
1935 |
default:
|
1936 |
abort(); |
1937 |
} |
1938 |
|
1939 |
data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }",
|
1940 |
bdrv->device_name, |
1941 |
action_str, |
1942 |
is_read ? "read" : "write"); |
1943 |
monitor_protocol_event(ev, data); |
1944 |
|
1945 |
qobject_decref(data); |
1946 |
} |
1947 |
|
1948 |
static void bdrv_emit_qmp_eject_event(BlockDriverState *bs, bool ejected) |
1949 |
{ |
1950 |
QObject *data; |
1951 |
|
1952 |
data = qobject_from_jsonf("{ 'device': %s, 'tray-open': %i }",
|
1953 |
bdrv_get_device_name(bs), ejected); |
1954 |
monitor_protocol_event(QEVENT_DEVICE_TRAY_MOVED, data); |
1955 |
|
1956 |
qobject_decref(data); |
1957 |
} |
1958 |
|
1959 |
static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load) |
1960 |
{ |
1961 |
if (bs->dev_ops && bs->dev_ops->change_media_cb) {
|
1962 |
bool tray_was_closed = !bdrv_dev_is_tray_open(bs);
|
1963 |
bs->dev_ops->change_media_cb(bs->dev_opaque, load); |
1964 |
if (tray_was_closed) {
|
1965 |
/* tray open */
|
1966 |
bdrv_emit_qmp_eject_event(bs, true);
|
1967 |
} |
1968 |
if (load) {
|
1969 |
/* tray close */
|
1970 |
bdrv_emit_qmp_eject_event(bs, false);
|
1971 |
} |
1972 |
} |
1973 |
} |
1974 |
|
1975 |
bool bdrv_dev_has_removable_media(BlockDriverState *bs)
|
1976 |
{ |
1977 |
return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb);
|
1978 |
} |
1979 |
|
1980 |
void bdrv_dev_eject_request(BlockDriverState *bs, bool force) |
1981 |
{ |
1982 |
if (bs->dev_ops && bs->dev_ops->eject_request_cb) {
|
1983 |
bs->dev_ops->eject_request_cb(bs->dev_opaque, force); |
1984 |
} |
1985 |
} |
1986 |
|
1987 |
bool bdrv_dev_is_tray_open(BlockDriverState *bs)
|
1988 |
{ |
1989 |
if (bs->dev_ops && bs->dev_ops->is_tray_open) {
|
1990 |
return bs->dev_ops->is_tray_open(bs->dev_opaque);
|
1991 |
} |
1992 |
return false; |
1993 |
} |
1994 |
|
1995 |
static void bdrv_dev_resize_cb(BlockDriverState *bs) |
1996 |
{ |
1997 |
if (bs->dev_ops && bs->dev_ops->resize_cb) {
|
1998 |
bs->dev_ops->resize_cb(bs->dev_opaque); |
1999 |
} |
2000 |
} |
2001 |
|
2002 |
bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
|
2003 |
{ |
2004 |
if (bs->dev_ops && bs->dev_ops->is_medium_locked) {
|
2005 |
return bs->dev_ops->is_medium_locked(bs->dev_opaque);
|
2006 |
} |
2007 |
return false; |
2008 |
} |
2009 |
|
2010 |
/*
|
2011 |
* Run consistency checks on an image
|
2012 |
*
|
2013 |
* Returns 0 if the check could be completed (it doesn't mean that the image is
|
2014 |
* free of errors) or -errno when an internal error occurred. The results of the
|
2015 |
* check are stored in res.
|
2016 |
*/
|
2017 |
int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
|
2018 |
{ |
2019 |
if (bs->drv->bdrv_check == NULL) { |
2020 |
return -ENOTSUP;
|
2021 |
} |
2022 |
|
2023 |
memset(res, 0, sizeof(*res)); |
2024 |
return bs->drv->bdrv_check(bs, res, fix);
|
2025 |
} |
2026 |
|
2027 |
#define COMMIT_BUF_SECTORS 2048 |
2028 |
|
2029 |
/* commit COW file into the raw image */
|
2030 |
int bdrv_commit(BlockDriverState *bs)
|
2031 |
{ |
2032 |
BlockDriver *drv = bs->drv; |
2033 |
int64_t sector, total_sectors; |
2034 |
int n, ro, open_flags;
|
2035 |
int ret = 0; |
2036 |
uint8_t *buf; |
2037 |
char filename[PATH_MAX];
|
2038 |
|
2039 |
if (!drv)
|
2040 |
return -ENOMEDIUM;
|
2041 |
|
2042 |
if (!bs->backing_hd) {
|
2043 |
return -ENOTSUP;
|
2044 |
} |
2045 |
|
2046 |
if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) {
|
2047 |
return -EBUSY;
|
2048 |
} |
2049 |
|
2050 |
ro = bs->backing_hd->read_only; |
2051 |
/* Use pstrcpy (not strncpy): filename must be NUL-terminated. */
|
2052 |
pstrcpy(filename, sizeof(filename), bs->backing_hd->filename);
|
2053 |
open_flags = bs->backing_hd->open_flags; |
2054 |
|
2055 |
if (ro) {
|
2056 |
if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) { |
2057 |
return -EACCES;
|
2058 |
} |
2059 |
} |
2060 |
|
2061 |
total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; |
2062 |
buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); |
2063 |
|
2064 |
for (sector = 0; sector < total_sectors; sector += n) { |
2065 |
ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n); |
2066 |
if (ret < 0) { |
2067 |
goto ro_cleanup;
|
2068 |
} |
2069 |
if (ret) {
|
2070 |
if (bdrv_read(bs, sector, buf, n) != 0) { |
2071 |
ret = -EIO; |
2072 |
goto ro_cleanup;
|
2073 |
} |
2074 |
|
2075 |
if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) { |
2076 |
ret = -EIO; |
2077 |
goto ro_cleanup;
|
2078 |
} |
2079 |
} |
2080 |
} |
2081 |
|
2082 |
if (drv->bdrv_make_empty) {
|
2083 |
ret = drv->bdrv_make_empty(bs); |
2084 |
bdrv_flush(bs); |
2085 |
} |
2086 |
|
2087 |
/*
|
2088 |
* Make sure all data we wrote to the backing device is actually
|
2089 |
* stable on disk.
|
2090 |
*/
|
2091 |
if (bs->backing_hd)
|
2092 |
bdrv_flush(bs->backing_hd); |
2093 |
|
2094 |
ro_cleanup:
|
2095 |
g_free(buf); |
2096 |
|
2097 |
if (ro) {
|
2098 |
/* ignoring error return here */
|
2099 |
bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
|
2100 |
} |
2101 |
|
2102 |
return ret;
|
2103 |
} |
2104 |
|
2105 |
int bdrv_commit_all(void) |
2106 |
{ |
2107 |
BlockDriverState *bs; |
2108 |
|
2109 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
2110 |
if (bs->drv && bs->backing_hd) {
|
2111 |
int ret = bdrv_commit(bs);
|
2112 |
if (ret < 0) { |
2113 |
return ret;
|
2114 |
} |
2115 |
} |
2116 |
} |
2117 |
return 0; |
2118 |
} |
2119 |
|
2120 |
/**
|
2121 |
* Remove an active request from the tracked requests list
|
2122 |
*
|
2123 |
* This function should be called when a tracked request is completing.
|
2124 |
*/
|
2125 |
static void tracked_request_end(BdrvTrackedRequest *req) |
2126 |
{ |
2127 |
QLIST_REMOVE(req, list); |
2128 |
qemu_co_queue_restart_all(&req->wait_queue); |
2129 |
} |
2130 |
|
2131 |
/**
|
2132 |
* Add an active request to the tracked requests list
|
2133 |
*/
|
2134 |
static void tracked_request_begin(BdrvTrackedRequest *req, |
2135 |
BlockDriverState *bs, |
2136 |
int64_t sector_num, |
2137 |
int nb_sectors, bool is_write) |
2138 |
{ |
2139 |
*req = (BdrvTrackedRequest){ |
2140 |
.bs = bs, |
2141 |
.sector_num = sector_num, |
2142 |
.nb_sectors = nb_sectors, |
2143 |
.is_write = is_write, |
2144 |
.co = qemu_coroutine_self(), |
2145 |
}; |
2146 |
|
2147 |
qemu_co_queue_init(&req->wait_queue); |
2148 |
|
2149 |
QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); |
2150 |
} |
2151 |
|
2152 |
/**
|
2153 |
* Round a region to cluster boundaries
|
2154 |
*/
|
2155 |
void bdrv_round_to_clusters(BlockDriverState *bs,
|
2156 |
int64_t sector_num, int nb_sectors,
|
2157 |
int64_t *cluster_sector_num, |
2158 |
int *cluster_nb_sectors)
|
2159 |
{ |
2160 |
BlockDriverInfo bdi; |
2161 |
|
2162 |
if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { |
2163 |
*cluster_sector_num = sector_num; |
2164 |
*cluster_nb_sectors = nb_sectors; |
2165 |
} else {
|
2166 |
int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; |
2167 |
*cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); |
2168 |
*cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + |
2169 |
nb_sectors, c); |
2170 |
} |
2171 |
} |
2172 |
|
2173 |
static bool tracked_request_overlaps(BdrvTrackedRequest *req, |
2174 |
int64_t sector_num, int nb_sectors) {
|
2175 |
/* aaaa bbbb */
|
2176 |
if (sector_num >= req->sector_num + req->nb_sectors) {
|
2177 |
return false; |
2178 |
} |
2179 |
/* bbbb aaaa */
|
2180 |
if (req->sector_num >= sector_num + nb_sectors) {
|
2181 |
return false; |
2182 |
} |
2183 |
return true; |
2184 |
} |
2185 |
|
2186 |
static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, |
2187 |
int64_t sector_num, int nb_sectors)
|
2188 |
{ |
2189 |
BdrvTrackedRequest *req; |
2190 |
int64_t cluster_sector_num; |
2191 |
int cluster_nb_sectors;
|
2192 |
bool retry;
|
2193 |
|
2194 |
/* If we touch the same cluster it counts as an overlap. This guarantees
|
2195 |
* that allocating writes will be serialized and not race with each other
|
2196 |
* for the same cluster. For example, in copy-on-read it ensures that the
|
2197 |
* CoR read and write operations are atomic and guest writes cannot
|
2198 |
* interleave between them.
|
2199 |
*/
|
2200 |
bdrv_round_to_clusters(bs, sector_num, nb_sectors, |
2201 |
&cluster_sector_num, &cluster_nb_sectors); |
2202 |
|
2203 |
do {
|
2204 |
retry = false;
|
2205 |
QLIST_FOREACH(req, &bs->tracked_requests, list) { |
2206 |
if (tracked_request_overlaps(req, cluster_sector_num,
|
2207 |
cluster_nb_sectors)) { |
2208 |
/* Hitting this means there was a reentrant request, for
|
2209 |
* example, a block driver issuing nested requests. This must
|
2210 |
* never happen since it means deadlock.
|
2211 |
*/
|
2212 |
assert(qemu_coroutine_self() != req->co); |
2213 |
|
2214 |
qemu_co_queue_wait(&req->wait_queue); |
2215 |
retry = true;
|
2216 |
break;
|
2217 |
} |
2218 |
} |
2219 |
} while (retry);
|
2220 |
} |
2221 |
|
2222 |
/*
|
2223 |
* Return values:
|
2224 |
* 0 - success
|
2225 |
* -EINVAL - backing format specified, but no file
|
2226 |
* -ENOSPC - can't update the backing file because no space is left in the
|
2227 |
* image file header
|
2228 |
* -ENOTSUP - format driver doesn't support changing the backing file
|
2229 |
*/
|
2230 |
int bdrv_change_backing_file(BlockDriverState *bs,
|
2231 |
const char *backing_file, const char *backing_fmt) |
2232 |
{ |
2233 |
BlockDriver *drv = bs->drv; |
2234 |
int ret;
|
2235 |
|
2236 |
/* Backing file format doesn't make sense without a backing file */
|
2237 |
if (backing_fmt && !backing_file) {
|
2238 |
return -EINVAL;
|
2239 |
} |
2240 |
|
2241 |
if (drv->bdrv_change_backing_file != NULL) { |
2242 |
ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); |
2243 |
} else {
|
2244 |
ret = -ENOTSUP; |
2245 |
} |
2246 |
|
2247 |
if (ret == 0) { |
2248 |
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
2249 |
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
2250 |
} |
2251 |
return ret;
|
2252 |
} |
2253 |
|
2254 |
/*
|
2255 |
* Finds the image layer in the chain that has 'bs' as its backing file.
|
2256 |
*
|
2257 |
* active is the current topmost image.
|
2258 |
*
|
2259 |
* Returns NULL if bs is not found in active's image chain,
|
2260 |
* or if active == bs.
|
2261 |
*/
|
2262 |
BlockDriverState *bdrv_find_overlay(BlockDriverState *active, |
2263 |
BlockDriverState *bs) |
2264 |
{ |
2265 |
BlockDriverState *overlay = NULL;
|
2266 |
BlockDriverState *intermediate; |
2267 |
|
2268 |
assert(active != NULL);
|
2269 |
assert(bs != NULL);
|
2270 |
|
2271 |
/* if bs is the same as active, then by definition it has no overlay
|
2272 |
*/
|
2273 |
if (active == bs) {
|
2274 |
return NULL; |
2275 |
} |
2276 |
|
2277 |
intermediate = active; |
2278 |
while (intermediate->backing_hd) {
|
2279 |
if (intermediate->backing_hd == bs) {
|
2280 |
overlay = intermediate; |
2281 |
break;
|
2282 |
} |
2283 |
intermediate = intermediate->backing_hd; |
2284 |
} |
2285 |
|
2286 |
return overlay;
|
2287 |
} |
2288 |
|
2289 |
typedef struct BlkIntermediateStates { |
2290 |
BlockDriverState *bs; |
2291 |
QSIMPLEQ_ENTRY(BlkIntermediateStates) entry; |
2292 |
} BlkIntermediateStates; |
2293 |
|
2294 |
|
2295 |
/*
|
2296 |
* Drops images above 'base' up to and including 'top', and sets the image
|
2297 |
* above 'top' to have base as its backing file.
|
2298 |
*
|
2299 |
* Requires that the overlay to 'top' is opened r/w, so that the backing file
|
2300 |
* information in 'bs' can be properly updated.
|
2301 |
*
|
2302 |
* E.g., this will convert the following chain:
|
2303 |
* bottom <- base <- intermediate <- top <- active
|
2304 |
*
|
2305 |
* to
|
2306 |
*
|
2307 |
* bottom <- base <- active
|
2308 |
*
|
2309 |
* It is allowed for bottom==base, in which case it converts:
|
2310 |
*
|
2311 |
* base <- intermediate <- top <- active
|
2312 |
*
|
2313 |
* to
|
2314 |
*
|
2315 |
* base <- active
|
2316 |
*
|
2317 |
* Error conditions:
|
2318 |
* if active == top, that is considered an error
|
2319 |
*
|
2320 |
*/
|
2321 |
int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
|
2322 |
BlockDriverState *base) |
2323 |
{ |
2324 |
BlockDriverState *intermediate; |
2325 |
BlockDriverState *base_bs = NULL;
|
2326 |
BlockDriverState *new_top_bs = NULL;
|
2327 |
BlkIntermediateStates *intermediate_state, *next; |
2328 |
int ret = -EIO;
|
2329 |
|
2330 |
QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete; |
2331 |
QSIMPLEQ_INIT(&states_to_delete); |
2332 |
|
2333 |
if (!top->drv || !base->drv) {
|
2334 |
goto exit;
|
2335 |
} |
2336 |
|
2337 |
new_top_bs = bdrv_find_overlay(active, top); |
2338 |
|
2339 |
if (new_top_bs == NULL) { |
2340 |
/* we could not find the image above 'top', this is an error */
|
2341 |
goto exit;
|
2342 |
} |
2343 |
|
2344 |
/* special case of new_top_bs->backing_hd already pointing to base - nothing
|
2345 |
* to do, no intermediate images */
|
2346 |
if (new_top_bs->backing_hd == base) {
|
2347 |
ret = 0;
|
2348 |
goto exit;
|
2349 |
} |
2350 |
|
2351 |
intermediate = top; |
2352 |
|
2353 |
/* now we will go down through the list, and add each BDS we find
|
2354 |
* into our deletion queue, until we hit the 'base'
|
2355 |
*/
|
2356 |
while (intermediate) {
|
2357 |
intermediate_state = g_malloc0(sizeof(BlkIntermediateStates));
|
2358 |
intermediate_state->bs = intermediate; |
2359 |
QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry); |
2360 |
|
2361 |
if (intermediate->backing_hd == base) {
|
2362 |
base_bs = intermediate->backing_hd; |
2363 |
break;
|
2364 |
} |
2365 |
intermediate = intermediate->backing_hd; |
2366 |
} |
2367 |
if (base_bs == NULL) { |
2368 |
/* something went wrong, we did not end at the base. safely
|
2369 |
* unravel everything, and exit with error */
|
2370 |
goto exit;
|
2371 |
} |
2372 |
|
2373 |
/* success - we can delete the intermediate states, and link top->base */
|
2374 |
ret = bdrv_change_backing_file(new_top_bs, base_bs->filename, |
2375 |
base_bs->drv ? base_bs->drv->format_name : "");
|
2376 |
if (ret) {
|
2377 |
goto exit;
|
2378 |
} |
2379 |
new_top_bs->backing_hd = base_bs; |
2380 |
|
2381 |
|
2382 |
QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { |
2383 |
/* so that bdrv_close() does not recursively close the chain */
|
2384 |
intermediate_state->bs->backing_hd = NULL;
|
2385 |
bdrv_unref(intermediate_state->bs); |
2386 |
} |
2387 |
ret = 0;
|
2388 |
|
2389 |
exit:
|
2390 |
QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { |
2391 |
g_free(intermediate_state); |
2392 |
} |
2393 |
return ret;
|
2394 |
} |
2395 |
|
2396 |
|
2397 |
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, |
2398 |
size_t size) |
2399 |
{ |
2400 |
int64_t len; |
2401 |
|
2402 |
if (!bdrv_is_inserted(bs))
|
2403 |
return -ENOMEDIUM;
|
2404 |
|
2405 |
if (bs->growable)
|
2406 |
return 0; |
2407 |
|
2408 |
len = bdrv_getlength(bs); |
2409 |
|
2410 |
if (offset < 0) |
2411 |
return -EIO;
|
2412 |
|
2413 |
if ((offset > len) || (len - offset < size))
|
2414 |
return -EIO;
|
2415 |
|
2416 |
return 0; |
2417 |
} |
2418 |
|
2419 |
static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, |
2420 |
int nb_sectors)
|
2421 |
{ |
2422 |
return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
|
2423 |
nb_sectors * BDRV_SECTOR_SIZE); |
2424 |
} |
2425 |
|
2426 |
typedef struct RwCo { |
2427 |
BlockDriverState *bs; |
2428 |
int64_t sector_num; |
2429 |
int nb_sectors;
|
2430 |
QEMUIOVector *qiov; |
2431 |
bool is_write;
|
2432 |
int ret;
|
2433 |
BdrvRequestFlags flags; |
2434 |
} RwCo; |
2435 |
|
2436 |
static void coroutine_fn bdrv_rw_co_entry(void *opaque) |
2437 |
{ |
2438 |
RwCo *rwco = opaque; |
2439 |
|
2440 |
if (!rwco->is_write) {
|
2441 |
rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num, |
2442 |
rwco->nb_sectors, rwco->qiov, |
2443 |
rwco->flags); |
2444 |
} else {
|
2445 |
rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num, |
2446 |
rwco->nb_sectors, rwco->qiov, |
2447 |
rwco->flags); |
2448 |
} |
2449 |
} |
2450 |
|
2451 |
/*
|
2452 |
* Process a vectored synchronous request using coroutines
|
2453 |
*/
|
2454 |
static int bdrv_rwv_co(BlockDriverState *bs, int64_t sector_num, |
2455 |
QEMUIOVector *qiov, bool is_write,
|
2456 |
BdrvRequestFlags flags) |
2457 |
{ |
2458 |
Coroutine *co; |
2459 |
RwCo rwco = { |
2460 |
.bs = bs, |
2461 |
.sector_num = sector_num, |
2462 |
.nb_sectors = qiov->size >> BDRV_SECTOR_BITS, |
2463 |
.qiov = qiov, |
2464 |
.is_write = is_write, |
2465 |
.ret = NOT_DONE, |
2466 |
.flags = flags, |
2467 |
}; |
2468 |
assert((qiov->size & (BDRV_SECTOR_SIZE - 1)) == 0); |
2469 |
|
2470 |
/**
|
2471 |
* In sync call context, when the vcpu is blocked, this throttling timer
|
2472 |
* will not fire; so the I/O throttling function has to be disabled here
|
2473 |
* if it has been enabled.
|
2474 |
*/
|
2475 |
if (bs->io_limits_enabled) {
|
2476 |
fprintf(stderr, "Disabling I/O throttling on '%s' due "
|
2477 |
"to synchronous I/O.\n", bdrv_get_device_name(bs));
|
2478 |
bdrv_io_limits_disable(bs); |
2479 |
} |
2480 |
|
2481 |
if (qemu_in_coroutine()) {
|
2482 |
/* Fast-path if already in coroutine context */
|
2483 |
bdrv_rw_co_entry(&rwco); |
2484 |
} else {
|
2485 |
co = qemu_coroutine_create(bdrv_rw_co_entry); |
2486 |
qemu_coroutine_enter(co, &rwco); |
2487 |
while (rwco.ret == NOT_DONE) {
|
2488 |
qemu_aio_wait(); |
2489 |
} |
2490 |
} |
2491 |
return rwco.ret;
|
2492 |
} |
2493 |
|
2494 |
/*
|
2495 |
* Process a synchronous request using coroutines
|
2496 |
*/
|
2497 |
static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, |
2498 |
int nb_sectors, bool is_write, BdrvRequestFlags flags) |
2499 |
{ |
2500 |
QEMUIOVector qiov; |
2501 |
struct iovec iov = {
|
2502 |
.iov_base = (void *)buf,
|
2503 |
.iov_len = nb_sectors * BDRV_SECTOR_SIZE, |
2504 |
}; |
2505 |
|
2506 |
qemu_iovec_init_external(&qiov, &iov, 1);
|
2507 |
return bdrv_rwv_co(bs, sector_num, &qiov, is_write, flags);
|
2508 |
} |
2509 |
|
2510 |
/* return < 0 if error. See bdrv_write() for the return codes */
|
2511 |
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
|
2512 |
uint8_t *buf, int nb_sectors)
|
2513 |
{ |
2514 |
return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0); |
2515 |
} |
2516 |
|
2517 |
/* Just like bdrv_read(), but with I/O throttling temporarily disabled */
|
2518 |
int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num,
|
2519 |
uint8_t *buf, int nb_sectors)
|
2520 |
{ |
2521 |
bool enabled;
|
2522 |
int ret;
|
2523 |
|
2524 |
enabled = bs->io_limits_enabled; |
2525 |
bs->io_limits_enabled = false;
|
2526 |
ret = bdrv_read(bs, sector_num, buf, nb_sectors); |
2527 |
bs->io_limits_enabled = enabled; |
2528 |
return ret;
|
2529 |
} |
2530 |
|
2531 |
/* Return < 0 if error. Important errors are:
|
2532 |
-EIO generic I/O error (may happen for all errors)
|
2533 |
-ENOMEDIUM No media inserted.
|
2534 |
-EINVAL Invalid sector number or nb_sectors
|
2535 |
-EACCES Trying to write a read-only device
|
2536 |
*/
|
2537 |
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
|
2538 |
const uint8_t *buf, int nb_sectors) |
2539 |
{ |
2540 |
return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0); |
2541 |
} |
2542 |
|
2543 |
int bdrv_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov)
|
2544 |
{ |
2545 |
return bdrv_rwv_co(bs, sector_num, qiov, true, 0); |
2546 |
} |
2547 |
|
2548 |
int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
|
2549 |
int nb_sectors, BdrvRequestFlags flags)
|
2550 |
{ |
2551 |
return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true, |
2552 |
BDRV_REQ_ZERO_WRITE | flags); |
2553 |
} |
2554 |
|
2555 |
/*
|
2556 |
* Completely zero out a block device with the help of bdrv_write_zeroes.
|
2557 |
* The operation is sped up by checking the block status and only writing
|
2558 |
* zeroes to the device if they currently do not return zeroes. Optional
|
2559 |
* flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP).
|
2560 |
*
|
2561 |
* Returns < 0 on error, 0 on success. For error codes see bdrv_write().
|
2562 |
*/
|
2563 |
int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
|
2564 |
{ |
2565 |
int64_t target_size = bdrv_getlength(bs) / BDRV_SECTOR_SIZE; |
2566 |
int64_t ret, nb_sectors, sector_num = 0;
|
2567 |
int n;
|
2568 |
|
2569 |
for (;;) {
|
2570 |
nb_sectors = target_size - sector_num; |
2571 |
if (nb_sectors <= 0) { |
2572 |
return 0; |
2573 |
} |
2574 |
if (nb_sectors > INT_MAX) {
|
2575 |
nb_sectors = INT_MAX; |
2576 |
} |
2577 |
ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n); |
2578 |
if (ret < 0) { |
2579 |
error_report("error getting block status at sector %" PRId64 ": %s", |
2580 |
sector_num, strerror(-ret)); |
2581 |
return ret;
|
2582 |
} |
2583 |
if (ret & BDRV_BLOCK_ZERO) {
|
2584 |
sector_num += n; |
2585 |
continue;
|
2586 |
} |
2587 |
ret = bdrv_write_zeroes(bs, sector_num, n, flags); |
2588 |
if (ret < 0) { |
2589 |
error_report("error writing zeroes at sector %" PRId64 ": %s", |
2590 |
sector_num, strerror(-ret)); |
2591 |
return ret;
|
2592 |
} |
2593 |
sector_num += n; |
2594 |
} |
2595 |
} |
2596 |
|
2597 |
int bdrv_pread(BlockDriverState *bs, int64_t offset,
|
2598 |
void *buf, int count1) |
2599 |
{ |
2600 |
uint8_t tmp_buf[BDRV_SECTOR_SIZE]; |
2601 |
int len, nb_sectors, count;
|
2602 |
int64_t sector_num; |
2603 |
int ret;
|
2604 |
|
2605 |
count = count1; |
2606 |
/* first read to align to sector start */
|
2607 |
len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
|
2608 |
if (len > count)
|
2609 |
len = count; |
2610 |
sector_num = offset >> BDRV_SECTOR_BITS; |
2611 |
if (len > 0) { |
2612 |
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
2613 |
return ret;
|
2614 |
memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
|
2615 |
count -= len; |
2616 |
if (count == 0) |
2617 |
return count1;
|
2618 |
sector_num++; |
2619 |
buf += len; |
2620 |
} |
2621 |
|
2622 |
/* read the sectors "in place" */
|
2623 |
nb_sectors = count >> BDRV_SECTOR_BITS; |
2624 |
if (nb_sectors > 0) { |
2625 |
if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0) |
2626 |
return ret;
|
2627 |
sector_num += nb_sectors; |
2628 |
len = nb_sectors << BDRV_SECTOR_BITS; |
2629 |
buf += len; |
2630 |
count -= len; |
2631 |
} |
2632 |
|
2633 |
/* add data from the last sector */
|
2634 |
if (count > 0) { |
2635 |
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
2636 |
return ret;
|
2637 |
memcpy(buf, tmp_buf, count); |
2638 |
} |
2639 |
return count1;
|
2640 |
} |
2641 |
|
2642 |
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
|
2643 |
{ |
2644 |
uint8_t tmp_buf[BDRV_SECTOR_SIZE]; |
2645 |
int len, nb_sectors, count;
|
2646 |
int64_t sector_num; |
2647 |
int ret;
|
2648 |
|
2649 |
count = qiov->size; |
2650 |
|
2651 |
/* first write to align to sector start */
|
2652 |
len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
|
2653 |
if (len > count)
|
2654 |
len = count; |
2655 |
sector_num = offset >> BDRV_SECTOR_BITS; |
2656 |
if (len > 0) { |
2657 |
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
2658 |
return ret;
|
2659 |
qemu_iovec_to_buf(qiov, 0, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), |
2660 |
len); |
2661 |
if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) |
2662 |
return ret;
|
2663 |
count -= len; |
2664 |
if (count == 0) |
2665 |
return qiov->size;
|
2666 |
sector_num++; |
2667 |
} |
2668 |
|
2669 |
/* write the sectors "in place" */
|
2670 |
nb_sectors = count >> BDRV_SECTOR_BITS; |
2671 |
if (nb_sectors > 0) { |
2672 |
QEMUIOVector qiov_inplace; |
2673 |
|
2674 |
qemu_iovec_init(&qiov_inplace, qiov->niov); |
2675 |
qemu_iovec_concat(&qiov_inplace, qiov, len, |
2676 |
nb_sectors << BDRV_SECTOR_BITS); |
2677 |
ret = bdrv_writev(bs, sector_num, &qiov_inplace); |
2678 |
qemu_iovec_destroy(&qiov_inplace); |
2679 |
if (ret < 0) { |
2680 |
return ret;
|
2681 |
} |
2682 |
|
2683 |
sector_num += nb_sectors; |
2684 |
len = nb_sectors << BDRV_SECTOR_BITS; |
2685 |
count -= len; |
2686 |
} |
2687 |
|
2688 |
/* add data from the last sector */
|
2689 |
if (count > 0) { |
2690 |
if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
2691 |
return ret;
|
2692 |
qemu_iovec_to_buf(qiov, qiov->size - count, tmp_buf, count); |
2693 |
if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) |
2694 |
return ret;
|
2695 |
} |
2696 |
return qiov->size;
|
2697 |
} |
2698 |
|
2699 |
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
|
2700 |
const void *buf, int count1) |
2701 |
{ |
2702 |
QEMUIOVector qiov; |
2703 |
struct iovec iov = {
|
2704 |
.iov_base = (void *) buf,
|
2705 |
.iov_len = count1, |
2706 |
}; |
2707 |
|
2708 |
qemu_iovec_init_external(&qiov, &iov, 1);
|
2709 |
return bdrv_pwritev(bs, offset, &qiov);
|
2710 |
} |
2711 |
|
2712 |
/*
|
2713 |
* Writes to the file and ensures that no writes are reordered across this
|
2714 |
* request (acts as a barrier)
|
2715 |
*
|
2716 |
* Returns 0 on success, -errno in error cases.
|
2717 |
*/
|
2718 |
int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
|
2719 |
const void *buf, int count) |
2720 |
{ |
2721 |
int ret;
|
2722 |
|
2723 |
ret = bdrv_pwrite(bs, offset, buf, count); |
2724 |
if (ret < 0) { |
2725 |
return ret;
|
2726 |
} |
2727 |
|
2728 |
/* No flush needed for cache modes that already do it */
|
2729 |
if (bs->enable_write_cache) {
|
2730 |
bdrv_flush(bs); |
2731 |
} |
2732 |
|
2733 |
return 0; |
2734 |
} |
2735 |
|
2736 |
static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, |
2737 |
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
|
2738 |
{ |
2739 |
/* Perform I/O through a temporary buffer so that users who scribble over
|
2740 |
* their read buffer while the operation is in progress do not end up
|
2741 |
* modifying the image file. This is critical for zero-copy guest I/O
|
2742 |
* where anything might happen inside guest memory.
|
2743 |
*/
|
2744 |
void *bounce_buffer;
|
2745 |
|
2746 |
BlockDriver *drv = bs->drv; |
2747 |
struct iovec iov;
|
2748 |
QEMUIOVector bounce_qiov; |
2749 |
int64_t cluster_sector_num; |
2750 |
int cluster_nb_sectors;
|
2751 |
size_t skip_bytes; |
2752 |
int ret;
|
2753 |
|
2754 |
/* Cover entire cluster so no additional backing file I/O is required when
|
2755 |
* allocating cluster in the image file.
|
2756 |
*/
|
2757 |
bdrv_round_to_clusters(bs, sector_num, nb_sectors, |
2758 |
&cluster_sector_num, &cluster_nb_sectors); |
2759 |
|
2760 |
trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, |
2761 |
cluster_sector_num, cluster_nb_sectors); |
2762 |
|
2763 |
iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; |
2764 |
iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len); |
2765 |
qemu_iovec_init_external(&bounce_qiov, &iov, 1);
|
2766 |
|
2767 |
ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, |
2768 |
&bounce_qiov); |
2769 |
if (ret < 0) { |
2770 |
goto err;
|
2771 |
} |
2772 |
|
2773 |
if (drv->bdrv_co_write_zeroes &&
|
2774 |
buffer_is_zero(bounce_buffer, iov.iov_len)) { |
2775 |
ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, |
2776 |
cluster_nb_sectors, 0);
|
2777 |
} else {
|
2778 |
/* This does not change the data on the disk, it is not necessary
|
2779 |
* to flush even in cache=writethrough mode.
|
2780 |
*/
|
2781 |
ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, |
2782 |
&bounce_qiov); |
2783 |
} |
2784 |
|
2785 |
if (ret < 0) { |
2786 |
/* It might be okay to ignore write errors for guest requests. If this
|
2787 |
* is a deliberate copy-on-read then we don't want to ignore the error.
|
2788 |
* Simply report it in all cases.
|
2789 |
*/
|
2790 |
goto err;
|
2791 |
} |
2792 |
|
2793 |
skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; |
2794 |
qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
|
2795 |
nb_sectors * BDRV_SECTOR_SIZE); |
2796 |
|
2797 |
err:
|
2798 |
qemu_vfree(bounce_buffer); |
2799 |
return ret;
|
2800 |
} |
2801 |
|
2802 |
/*
|
2803 |
* Handle a read request in coroutine context
|
2804 |
*/
|
2805 |
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, |
2806 |
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
|
2807 |
BdrvRequestFlags flags) |
2808 |
{ |
2809 |
BlockDriver *drv = bs->drv; |
2810 |
BdrvTrackedRequest req; |
2811 |
int ret;
|
2812 |
|
2813 |
if (!drv) {
|
2814 |
return -ENOMEDIUM;
|
2815 |
} |
2816 |
if (bdrv_check_request(bs, sector_num, nb_sectors)) {
|
2817 |
return -EIO;
|
2818 |
} |
2819 |
|
2820 |
if (bs->copy_on_read) {
|
2821 |
flags |= BDRV_REQ_COPY_ON_READ; |
2822 |
} |
2823 |
if (flags & BDRV_REQ_COPY_ON_READ) {
|
2824 |
bs->copy_on_read_in_flight++; |
2825 |
} |
2826 |
|
2827 |
if (bs->copy_on_read_in_flight) {
|
2828 |
wait_for_overlapping_requests(bs, sector_num, nb_sectors); |
2829 |
} |
2830 |
|
2831 |
/* throttling disk I/O */
|
2832 |
if (bs->io_limits_enabled) {
|
2833 |
bdrv_io_limits_intercept(bs, nb_sectors, false);
|
2834 |
} |
2835 |
|
2836 |
tracked_request_begin(&req, bs, sector_num, nb_sectors, false);
|
2837 |
|
2838 |
if (flags & BDRV_REQ_COPY_ON_READ) {
|
2839 |
int pnum;
|
2840 |
|
2841 |
ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum); |
2842 |
if (ret < 0) { |
2843 |
goto out;
|
2844 |
} |
2845 |
|
2846 |
if (!ret || pnum != nb_sectors) {
|
2847 |
ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); |
2848 |
goto out;
|
2849 |
} |
2850 |
} |
2851 |
|
2852 |
if (!(bs->zero_beyond_eof && bs->growable)) {
|
2853 |
ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); |
2854 |
} else {
|
2855 |
/* Read zeros after EOF of growable BDSes */
|
2856 |
int64_t len, total_sectors, max_nb_sectors; |
2857 |
|
2858 |
len = bdrv_getlength(bs); |
2859 |
if (len < 0) { |
2860 |
ret = len; |
2861 |
goto out;
|
2862 |
} |
2863 |
|
2864 |
total_sectors = DIV_ROUND_UP(len, BDRV_SECTOR_SIZE); |
2865 |
max_nb_sectors = MAX(0, total_sectors - sector_num);
|
2866 |
if (max_nb_sectors > 0) { |
2867 |
ret = drv->bdrv_co_readv(bs, sector_num, |
2868 |
MIN(nb_sectors, max_nb_sectors), qiov); |
2869 |
} else {
|
2870 |
ret = 0;
|
2871 |
} |
2872 |
|
2873 |
/* Reading beyond end of file is supposed to produce zeroes */
|
2874 |
if (ret == 0 && total_sectors < sector_num + nb_sectors) { |
2875 |
uint64_t offset = MAX(0, total_sectors - sector_num);
|
2876 |
uint64_t bytes = (sector_num + nb_sectors - offset) * |
2877 |
BDRV_SECTOR_SIZE; |
2878 |
qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
|
2879 |
} |
2880 |
} |
2881 |
|
2882 |
out:
|
2883 |
tracked_request_end(&req); |
2884 |
|
2885 |
if (flags & BDRV_REQ_COPY_ON_READ) {
|
2886 |
bs->copy_on_read_in_flight--; |
2887 |
} |
2888 |
|
2889 |
return ret;
|
2890 |
} |
2891 |
|
2892 |
int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
|
2893 |
int nb_sectors, QEMUIOVector *qiov)
|
2894 |
{ |
2895 |
trace_bdrv_co_readv(bs, sector_num, nb_sectors); |
2896 |
|
2897 |
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); |
2898 |
} |
2899 |
|
2900 |
int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs,
|
2901 |
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
|
2902 |
{ |
2903 |
trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); |
2904 |
|
2905 |
return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov,
|
2906 |
BDRV_REQ_COPY_ON_READ); |
2907 |
} |
2908 |
|
2909 |
/* if no limit is specified in the BlockLimits use a default
|
2910 |
* of 32768 512-byte sectors (16 MiB) per request.
|
2911 |
*/
|
2912 |
#define MAX_WRITE_ZEROES_DEFAULT 32768 |
2913 |
|
2914 |
static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, |
2915 |
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
|
2916 |
{ |
2917 |
BlockDriver *drv = bs->drv; |
2918 |
QEMUIOVector qiov; |
2919 |
struct iovec iov = {0}; |
2920 |
int ret = 0; |
2921 |
|
2922 |
int max_write_zeroes = bs->bl.max_write_zeroes ?
|
2923 |
bs->bl.max_write_zeroes : MAX_WRITE_ZEROES_DEFAULT; |
2924 |
|
2925 |
while (nb_sectors > 0 && !ret) { |
2926 |
int num = nb_sectors;
|
2927 |
|
2928 |
/* Align request. Block drivers can expect the "bulk" of the request
|
2929 |
* to be aligned.
|
2930 |
*/
|
2931 |
if (bs->bl.write_zeroes_alignment
|
2932 |
&& num > bs->bl.write_zeroes_alignment) { |
2933 |
if (sector_num % bs->bl.write_zeroes_alignment != 0) { |
2934 |
/* Make a small request up to the first aligned sector. */
|
2935 |
num = bs->bl.write_zeroes_alignment; |
2936 |
num -= sector_num % bs->bl.write_zeroes_alignment; |
2937 |
} else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) { |
2938 |
/* Shorten the request to the last aligned sector. num cannot
|
2939 |
* underflow because num > bs->bl.write_zeroes_alignment.
|
2940 |
*/
|
2941 |
num -= (sector_num + num) % bs->bl.write_zeroes_alignment; |
2942 |
} |
2943 |
} |
2944 |
|
2945 |
/* limit request size */
|
2946 |
if (num > max_write_zeroes) {
|
2947 |
num = max_write_zeroes; |
2948 |
} |
2949 |
|
2950 |
ret = -ENOTSUP; |
2951 |
/* First try the efficient write zeroes operation */
|
2952 |
if (drv->bdrv_co_write_zeroes) {
|
2953 |
ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); |
2954 |
} |
2955 |
|
2956 |
if (ret == -ENOTSUP) {
|
2957 |
/* Fall back to bounce buffer if write zeroes is unsupported */
|
2958 |
iov.iov_len = num * BDRV_SECTOR_SIZE; |
2959 |
if (iov.iov_base == NULL) { |
2960 |
iov.iov_base = qemu_blockalign(bs, num * BDRV_SECTOR_SIZE); |
2961 |
memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE);
|
2962 |
} |
2963 |
qemu_iovec_init_external(&qiov, &iov, 1);
|
2964 |
|
2965 |
ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov); |
2966 |
|
2967 |
/* Keep bounce buffer around if it is big enough for all
|
2968 |
* all future requests.
|
2969 |
*/
|
2970 |
if (num < max_write_zeroes) {
|
2971 |
qemu_vfree(iov.iov_base); |
2972 |
iov.iov_base = NULL;
|
2973 |
} |
2974 |
} |
2975 |
|
2976 |
sector_num += num; |
2977 |
nb_sectors -= num; |
2978 |
} |
2979 |
|
2980 |
qemu_vfree(iov.iov_base); |
2981 |
return ret;
|
2982 |
} |
2983 |
|
2984 |
/*
|
2985 |
* Handle a write request in coroutine context
|
2986 |
*/
|
2987 |
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, |
2988 |
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
|
2989 |
BdrvRequestFlags flags) |
2990 |
{ |
2991 |
BlockDriver *drv = bs->drv; |
2992 |
BdrvTrackedRequest req; |
2993 |
int ret;
|
2994 |
|
2995 |
if (!bs->drv) {
|
2996 |
return -ENOMEDIUM;
|
2997 |
} |
2998 |
if (bs->read_only) {
|
2999 |
return -EACCES;
|
3000 |
} |
3001 |
if (bdrv_check_request(bs, sector_num, nb_sectors)) {
|
3002 |
return -EIO;
|
3003 |
} |
3004 |
|
3005 |
if (bs->copy_on_read_in_flight) {
|
3006 |
wait_for_overlapping_requests(bs, sector_num, nb_sectors); |
3007 |
} |
3008 |
|
3009 |
/* throttling disk I/O */
|
3010 |
if (bs->io_limits_enabled) {
|
3011 |
bdrv_io_limits_intercept(bs, nb_sectors, true);
|
3012 |
} |
3013 |
|
3014 |
tracked_request_begin(&req, bs, sector_num, nb_sectors, true);
|
3015 |
|
3016 |
ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); |
3017 |
|
3018 |
if (ret < 0) { |
3019 |
/* Do nothing, write notifier decided to fail this request */
|
3020 |
} else if (flags & BDRV_REQ_ZERO_WRITE) { |
3021 |
ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); |
3022 |
} else {
|
3023 |
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); |
3024 |
} |
3025 |
|
3026 |
if (ret == 0 && !bs->enable_write_cache) { |
3027 |
ret = bdrv_co_flush(bs); |
3028 |
} |
3029 |
|
3030 |
bdrv_set_dirty(bs, sector_num, nb_sectors); |
3031 |
|
3032 |
if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { |
3033 |
bs->wr_highest_sector = sector_num + nb_sectors - 1;
|
3034 |
} |
3035 |
if (bs->growable && ret >= 0) { |
3036 |
bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); |
3037 |
} |
3038 |
|
3039 |
tracked_request_end(&req); |
3040 |
|
3041 |
return ret;
|
3042 |
} |
3043 |
|
3044 |
int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
|
3045 |
int nb_sectors, QEMUIOVector *qiov)
|
3046 |
{ |
3047 |
trace_bdrv_co_writev(bs, sector_num, nb_sectors); |
3048 |
|
3049 |
return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); |
3050 |
} |
3051 |
|
3052 |
int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
|
3053 |
int64_t sector_num, int nb_sectors,
|
3054 |
BdrvRequestFlags flags) |
3055 |
{ |
3056 |
trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags); |
3057 |
|
3058 |
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
3059 |
flags &= ~BDRV_REQ_MAY_UNMAP; |
3060 |
} |
3061 |
|
3062 |
return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, |
3063 |
BDRV_REQ_ZERO_WRITE | flags); |
3064 |
} |
3065 |
|
3066 |
/**
|
3067 |
* Truncate file to 'offset' bytes (needed only for file protocols)
|
3068 |
*/
|
3069 |
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
|
3070 |
{ |
3071 |
BlockDriver *drv = bs->drv; |
3072 |
int ret;
|
3073 |
if (!drv)
|
3074 |
return -ENOMEDIUM;
|
3075 |
if (!drv->bdrv_truncate)
|
3076 |
return -ENOTSUP;
|
3077 |
if (bs->read_only)
|
3078 |
return -EACCES;
|
3079 |
if (bdrv_in_use(bs))
|
3080 |
return -EBUSY;
|
3081 |
ret = drv->bdrv_truncate(bs, offset); |
3082 |
if (ret == 0) { |
3083 |
ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); |
3084 |
bdrv_dev_resize_cb(bs); |
3085 |
} |
3086 |
return ret;
|
3087 |
} |
3088 |
|
3089 |
/**
|
3090 |
* Length of a allocated file in bytes. Sparse files are counted by actual
|
3091 |
* allocated space. Return < 0 if error or unknown.
|
3092 |
*/
|
3093 |
int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) |
3094 |
{ |
3095 |
BlockDriver *drv = bs->drv; |
3096 |
if (!drv) {
|
3097 |
return -ENOMEDIUM;
|
3098 |
} |
3099 |
if (drv->bdrv_get_allocated_file_size) {
|
3100 |
return drv->bdrv_get_allocated_file_size(bs);
|
3101 |
} |
3102 |
if (bs->file) {
|
3103 |
return bdrv_get_allocated_file_size(bs->file);
|
3104 |
} |
3105 |
return -ENOTSUP;
|
3106 |
} |
3107 |
|
3108 |
/**
|
3109 |
* Length of a file in bytes. Return < 0 if error or unknown.
|
3110 |
*/
|
3111 |
int64_t bdrv_getlength(BlockDriverState *bs) |
3112 |
{ |
3113 |
BlockDriver *drv = bs->drv; |
3114 |
if (!drv)
|
3115 |
return -ENOMEDIUM;
|
3116 |
|
3117 |
if (drv->has_variable_length) {
|
3118 |
int ret = refresh_total_sectors(bs, bs->total_sectors);
|
3119 |
if (ret < 0) { |
3120 |
return ret;
|
3121 |
} |
3122 |
} |
3123 |
return bs->total_sectors * BDRV_SECTOR_SIZE;
|
3124 |
} |
3125 |
|
3126 |
/* return 0 as number of sectors if no device present or error */
|
3127 |
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
|
3128 |
{ |
3129 |
int64_t length; |
3130 |
length = bdrv_getlength(bs); |
3131 |
if (length < 0) |
3132 |
length = 0;
|
3133 |
else
|
3134 |
length = length >> BDRV_SECTOR_BITS; |
3135 |
*nb_sectors_ptr = length; |
3136 |
} |
3137 |
|
3138 |
void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
|
3139 |
BlockdevOnError on_write_error) |
3140 |
{ |
3141 |
bs->on_read_error = on_read_error; |
3142 |
bs->on_write_error = on_write_error; |
3143 |
} |
3144 |
|
3145 |
BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read)
|
3146 |
{ |
3147 |
return is_read ? bs->on_read_error : bs->on_write_error;
|
3148 |
} |
3149 |
|
3150 |
BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error) |
3151 |
{ |
3152 |
BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error; |
3153 |
|
3154 |
switch (on_err) {
|
3155 |
case BLOCKDEV_ON_ERROR_ENOSPC:
|
3156 |
return (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT;
|
3157 |
case BLOCKDEV_ON_ERROR_STOP:
|
3158 |
return BDRV_ACTION_STOP;
|
3159 |
case BLOCKDEV_ON_ERROR_REPORT:
|
3160 |
return BDRV_ACTION_REPORT;
|
3161 |
case BLOCKDEV_ON_ERROR_IGNORE:
|
3162 |
return BDRV_ACTION_IGNORE;
|
3163 |
default:
|
3164 |
abort(); |
3165 |
} |
3166 |
} |
3167 |
|
3168 |
/* This is done by device models because, while the block layer knows
|
3169 |
* about the error, it does not know whether an operation comes from
|
3170 |
* the device or the block layer (from a job, for example).
|
3171 |
*/
|
3172 |
void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
|
3173 |
bool is_read, int error) |
3174 |
{ |
3175 |
assert(error >= 0);
|
3176 |
bdrv_emit_qmp_error_event(bs, QEVENT_BLOCK_IO_ERROR, action, is_read); |
3177 |
if (action == BDRV_ACTION_STOP) {
|
3178 |
vm_stop(RUN_STATE_IO_ERROR); |
3179 |
bdrv_iostatus_set_err(bs, error); |
3180 |
} |
3181 |
} |
3182 |
|
3183 |
int bdrv_is_read_only(BlockDriverState *bs)
|
3184 |
{ |
3185 |
return bs->read_only;
|
3186 |
} |
3187 |
|
3188 |
int bdrv_is_sg(BlockDriverState *bs)
|
3189 |
{ |
3190 |
return bs->sg;
|
3191 |
} |
3192 |
|
3193 |
int bdrv_enable_write_cache(BlockDriverState *bs)
|
3194 |
{ |
3195 |
return bs->enable_write_cache;
|
3196 |
} |
3197 |
|
3198 |
void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce) |
3199 |
{ |
3200 |
bs->enable_write_cache = wce; |
3201 |
|
3202 |
/* so a reopen() will preserve wce */
|
3203 |
if (wce) {
|
3204 |
bs->open_flags |= BDRV_O_CACHE_WB; |
3205 |
} else {
|
3206 |
bs->open_flags &= ~BDRV_O_CACHE_WB; |
3207 |
} |
3208 |
} |
3209 |
|
3210 |
int bdrv_is_encrypted(BlockDriverState *bs)
|
3211 |
{ |
3212 |
if (bs->backing_hd && bs->backing_hd->encrypted)
|
3213 |
return 1; |
3214 |
return bs->encrypted;
|
3215 |
} |
3216 |
|
3217 |
int bdrv_key_required(BlockDriverState *bs)
|
3218 |
{ |
3219 |
BlockDriverState *backing_hd = bs->backing_hd; |
3220 |
|
3221 |
if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
|
3222 |
return 1; |
3223 |
return (bs->encrypted && !bs->valid_key);
|
3224 |
} |
3225 |
|
3226 |
int bdrv_set_key(BlockDriverState *bs, const char *key) |
3227 |
{ |
3228 |
int ret;
|
3229 |
if (bs->backing_hd && bs->backing_hd->encrypted) {
|
3230 |
ret = bdrv_set_key(bs->backing_hd, key); |
3231 |
if (ret < 0) |
3232 |
return ret;
|
3233 |
if (!bs->encrypted)
|
3234 |
return 0; |
3235 |
} |
3236 |
if (!bs->encrypted) {
|
3237 |
return -EINVAL;
|
3238 |
} else if (!bs->drv || !bs->drv->bdrv_set_key) { |
3239 |
return -ENOMEDIUM;
|
3240 |
} |
3241 |
ret = bs->drv->bdrv_set_key(bs, key); |
3242 |
if (ret < 0) { |
3243 |
bs->valid_key = 0;
|
3244 |
} else if (!bs->valid_key) { |
3245 |
bs->valid_key = 1;
|
3246 |
/* call the change callback now, we skipped it on open */
|
3247 |
bdrv_dev_change_media_cb(bs, true);
|
3248 |
} |
3249 |
return ret;
|
3250 |
} |
3251 |
|
3252 |
const char *bdrv_get_format_name(BlockDriverState *bs) |
3253 |
{ |
3254 |
return bs->drv ? bs->drv->format_name : NULL; |
3255 |
} |
3256 |
|
3257 |
void bdrv_iterate_format(void (*it)(void *opaque, const char *name), |
3258 |
void *opaque)
|
3259 |
{ |
3260 |
BlockDriver *drv; |
3261 |
|
3262 |
QLIST_FOREACH(drv, &bdrv_drivers, list) { |
3263 |
it(opaque, drv->format_name); |
3264 |
} |
3265 |
} |
3266 |
|
3267 |
/* This function is to find block backend bs */
|
3268 |
BlockDriverState *bdrv_find(const char *name) |
3269 |
{ |
3270 |
BlockDriverState *bs; |
3271 |
|
3272 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
3273 |
if (!strcmp(name, bs->device_name)) {
|
3274 |
return bs;
|
3275 |
} |
3276 |
} |
3277 |
return NULL; |
3278 |
} |
3279 |
|
3280 |
/* This function is to find a node in the bs graph */
|
3281 |
BlockDriverState *bdrv_find_node(const char *node_name) |
3282 |
{ |
3283 |
BlockDriverState *bs; |
3284 |
|
3285 |
assert(node_name); |
3286 |
|
3287 |
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
3288 |
if (!strcmp(node_name, bs->node_name)) {
|
3289 |
return bs;
|
3290 |
} |
3291 |
} |
3292 |
return NULL; |
3293 |
} |
3294 |
|
3295 |
/* Put this QMP function here so it can access the static graph_bdrv_states. */
|
3296 |
BlockDeviceInfoList *bdrv_named_nodes_list(void)
|
3297 |
{ |
3298 |
BlockDeviceInfoList *list, *entry; |
3299 |
BlockDriverState *bs; |
3300 |
|
3301 |
list = NULL;
|
3302 |
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
3303 |
entry = g_malloc0(sizeof(*entry));
|
3304 |
entry->value = bdrv_block_device_info(bs); |
3305 |
entry->next = list; |
3306 |
list = entry; |
3307 |
} |
3308 |
|
3309 |
return list;
|
3310 |
} |
3311 |
|
3312 |
BlockDriverState *bdrv_lookup_bs(const char *device, |
3313 |
const char *node_name, |
3314 |
Error **errp) |
3315 |
{ |
3316 |
BlockDriverState *bs = NULL;
|
3317 |
|
3318 |
if ((!device && !node_name) || (device && node_name)) {
|
3319 |
error_setg(errp, "Use either device or node-name but not both");
|
3320 |
return NULL; |
3321 |
} |
3322 |
|
3323 |
if (device) {
|
3324 |
bs = bdrv_find(device); |
3325 |
|
3326 |
if (!bs) {
|
3327 |
error_set(errp, QERR_DEVICE_NOT_FOUND, device); |
3328 |
return NULL; |
3329 |
} |
3330 |
|
3331 |
return bs;
|
3332 |
} |
3333 |
|
3334 |
bs = bdrv_find_node(node_name); |
3335 |
|
3336 |
if (!bs) {
|
3337 |
error_set(errp, QERR_DEVICE_NOT_FOUND, node_name); |
3338 |
return NULL; |
3339 |
} |
3340 |
|
3341 |
return bs;
|
3342 |
} |
3343 |
|
3344 |
BlockDriverState *bdrv_next(BlockDriverState *bs) |
3345 |
{ |
3346 |
if (!bs) {
|
3347 |
return QTAILQ_FIRST(&bdrv_states);
|
3348 |
} |
3349 |
return QTAILQ_NEXT(bs, device_list);
|
3350 |
} |
3351 |
|
3352 |
void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) |
3353 |
{ |
3354 |
BlockDriverState *bs; |
3355 |
|
3356 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
3357 |
it(opaque, bs); |
3358 |
} |
3359 |
} |
3360 |
|
3361 |
const char *bdrv_get_device_name(BlockDriverState *bs) |
3362 |
{ |
3363 |
return bs->device_name;
|
3364 |
} |
3365 |
|
3366 |
int bdrv_get_flags(BlockDriverState *bs)
|
3367 |
{ |
3368 |
return bs->open_flags;
|
3369 |
} |
3370 |
|
3371 |
int bdrv_flush_all(void) |
3372 |
{ |
3373 |
BlockDriverState *bs; |
3374 |
int result = 0; |
3375 |
|
3376 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
3377 |
int ret = bdrv_flush(bs);
|
3378 |
if (ret < 0 && !result) { |
3379 |
result = ret; |
3380 |
} |
3381 |
} |
3382 |
|
3383 |
return result;
|
3384 |
} |
3385 |
|
3386 |
int bdrv_has_zero_init_1(BlockDriverState *bs)
|
3387 |
{ |
3388 |
return 1; |
3389 |
} |
3390 |
|
3391 |
int bdrv_has_zero_init(BlockDriverState *bs)
|
3392 |
{ |
3393 |
assert(bs->drv); |
3394 |
|
3395 |
/* If BS is a copy on write image, it is initialized to
|
3396 |
the contents of the base image, which may not be zeroes. */
|
3397 |
if (bs->backing_hd) {
|
3398 |
return 0; |
3399 |
} |
3400 |
if (bs->drv->bdrv_has_zero_init) {
|
3401 |
return bs->drv->bdrv_has_zero_init(bs);
|
3402 |
} |
3403 |
|
3404 |
/* safe default */
|
3405 |
return 0; |
3406 |
} |
3407 |
|
3408 |
bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
|
3409 |
{ |
3410 |
BlockDriverInfo bdi; |
3411 |
|
3412 |
if (bs->backing_hd) {
|
3413 |
return false; |
3414 |
} |
3415 |
|
3416 |
if (bdrv_get_info(bs, &bdi) == 0) { |
3417 |
return bdi.unallocated_blocks_are_zero;
|
3418 |
} |
3419 |
|
3420 |
return false; |
3421 |
} |
3422 |
|
3423 |
bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
|
3424 |
{ |
3425 |
BlockDriverInfo bdi; |
3426 |
|
3427 |
if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
|
3428 |
return false; |
3429 |
} |
3430 |
|
3431 |
if (bdrv_get_info(bs, &bdi) == 0) { |
3432 |
return bdi.can_write_zeroes_with_unmap;
|
3433 |
} |
3434 |
|
3435 |
return false; |
3436 |
} |
3437 |
|
3438 |
typedef struct BdrvCoGetBlockStatusData { |
3439 |
BlockDriverState *bs; |
3440 |
BlockDriverState *base; |
3441 |
int64_t sector_num; |
3442 |
int nb_sectors;
|
3443 |
int *pnum;
|
3444 |
int64_t ret; |
3445 |
bool done;
|
3446 |
} BdrvCoGetBlockStatusData; |
3447 |
|
3448 |
/*
|
3449 |
* Returns true iff the specified sector is present in the disk image. Drivers
|
3450 |
* not implementing the functionality are assumed to not support backing files,
|
3451 |
* hence all their sectors are reported as allocated.
|
3452 |
*
|
3453 |
* If 'sector_num' is beyond the end of the disk image the return value is 0
|
3454 |
* and 'pnum' is set to 0.
|
3455 |
*
|
3456 |
* 'pnum' is set to the number of sectors (including and immediately following
|
3457 |
* the specified sector) that are known to be in the same
|
3458 |
* allocated/unallocated state.
|
3459 |
*
|
3460 |
* 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes
|
3461 |
* beyond the end of the disk image it will be clamped.
|
3462 |
*/
|
3463 |
static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
|
3464 |
int64_t sector_num, |
3465 |
int nb_sectors, int *pnum) |
3466 |
{ |
3467 |
int64_t length; |
3468 |
int64_t n; |
3469 |
int64_t ret, ret2; |
3470 |
|
3471 |
length = bdrv_getlength(bs); |
3472 |
if (length < 0) { |
3473 |
return length;
|
3474 |
} |
3475 |
|
3476 |
if (sector_num >= (length >> BDRV_SECTOR_BITS)) {
|
3477 |
*pnum = 0;
|
3478 |
return 0; |
3479 |
} |
3480 |
|
3481 |
n = bs->total_sectors - sector_num; |
3482 |
if (n < nb_sectors) {
|
3483 |
nb_sectors = n; |
3484 |
} |
3485 |
|
3486 |
if (!bs->drv->bdrv_co_get_block_status) {
|
3487 |
*pnum = nb_sectors; |
3488 |
ret = BDRV_BLOCK_DATA; |
3489 |
if (bs->drv->protocol_name) {
|
3490 |
ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE); |
3491 |
} |
3492 |
return ret;
|
3493 |
} |
3494 |
|
3495 |
ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum); |
3496 |
if (ret < 0) { |
3497 |
*pnum = 0;
|
3498 |
return ret;
|
3499 |
} |
3500 |
|
3501 |
if (ret & BDRV_BLOCK_RAW) {
|
3502 |
assert(ret & BDRV_BLOCK_OFFSET_VALID); |
3503 |
return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
|
3504 |
*pnum, pnum); |
3505 |
} |
3506 |
|
3507 |
if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
|
3508 |
if (bdrv_unallocated_blocks_are_zero(bs)) {
|
3509 |
ret |= BDRV_BLOCK_ZERO; |
3510 |
} else if (bs->backing_hd) { |
3511 |
BlockDriverState *bs2 = bs->backing_hd; |
3512 |
int64_t length2 = bdrv_getlength(bs2); |
3513 |
if (length2 >= 0 && sector_num >= (length2 >> BDRV_SECTOR_BITS)) { |
3514 |
ret |= BDRV_BLOCK_ZERO; |
3515 |
} |
3516 |
} |
3517 |
} |
3518 |
|
3519 |
if (bs->file &&
|
3520 |
(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && |
3521 |
(ret & BDRV_BLOCK_OFFSET_VALID)) { |
3522 |
ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS, |
3523 |
*pnum, pnum); |
3524 |
if (ret2 >= 0) { |
3525 |
/* Ignore errors. This is just providing extra information, it
|
3526 |
* is useful but not necessary.
|
3527 |
*/
|
3528 |
ret |= (ret2 & BDRV_BLOCK_ZERO); |
3529 |
} |
3530 |
} |
3531 |
|
3532 |
return ret;
|
3533 |
} |
3534 |
|
3535 |
/* Coroutine wrapper for bdrv_get_block_status() */
|
3536 |
static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque) |
3537 |
{ |
3538 |
BdrvCoGetBlockStatusData *data = opaque; |
3539 |
BlockDriverState *bs = data->bs; |
3540 |
|
3541 |
data->ret = bdrv_co_get_block_status(bs, data->sector_num, data->nb_sectors, |
3542 |
data->pnum); |
3543 |
data->done = true;
|
3544 |
} |
3545 |
|
3546 |
/*
|
3547 |
* Synchronous wrapper around bdrv_co_get_block_status().
|
3548 |
*
|
3549 |
* See bdrv_co_get_block_status() for details.
|
3550 |
*/
|
3551 |
int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num, |
3552 |
int nb_sectors, int *pnum) |
3553 |
{ |
3554 |
Coroutine *co; |
3555 |
BdrvCoGetBlockStatusData data = { |
3556 |
.bs = bs, |
3557 |
.sector_num = sector_num, |
3558 |
.nb_sectors = nb_sectors, |
3559 |
.pnum = pnum, |
3560 |
.done = false,
|
3561 |
}; |
3562 |
|
3563 |
if (qemu_in_coroutine()) {
|
3564 |
/* Fast-path if already in coroutine context */
|
3565 |
bdrv_get_block_status_co_entry(&data); |
3566 |
} else {
|
3567 |
co = qemu_coroutine_create(bdrv_get_block_status_co_entry); |
3568 |
qemu_coroutine_enter(co, &data); |
3569 |
while (!data.done) {
|
3570 |
qemu_aio_wait(); |
3571 |
} |
3572 |
} |
3573 |
return data.ret;
|
3574 |
} |
3575 |
|
3576 |
int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
3577 |
int nb_sectors, int *pnum) |
3578 |
{ |
3579 |
int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum); |
3580 |
if (ret < 0) { |
3581 |
return ret;
|
3582 |
} |
3583 |
return
|
3584 |
(ret & BDRV_BLOCK_DATA) || |
3585 |
((ret & BDRV_BLOCK_ZERO) && !bdrv_has_zero_init(bs)); |
3586 |
} |
3587 |
|
3588 |
/*
|
3589 |
* Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
|
3590 |
*
|
3591 |
* Return true if the given sector is allocated in any image between
|
3592 |
* BASE and TOP (inclusive). BASE can be NULL to check if the given
|
3593 |
* sector is allocated in any image of the chain. Return false otherwise.
|
3594 |
*
|
3595 |
* 'pnum' is set to the number of sectors (including and immediately following
|
3596 |
* the specified sector) that are known to be in the same
|
3597 |
* allocated/unallocated state.
|
3598 |
*
|
3599 |
*/
|
3600 |
int bdrv_is_allocated_above(BlockDriverState *top,
|
3601 |
BlockDriverState *base, |
3602 |
int64_t sector_num, |
3603 |
int nb_sectors, int *pnum) |
3604 |
{ |
3605 |
BlockDriverState *intermediate; |
3606 |
int ret, n = nb_sectors;
|
3607 |
|
3608 |
intermediate = top; |
3609 |
while (intermediate && intermediate != base) {
|
3610 |
int pnum_inter;
|
3611 |
ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors, |
3612 |
&pnum_inter); |
3613 |
if (ret < 0) { |
3614 |
return ret;
|
3615 |
} else if (ret) { |
3616 |
*pnum = pnum_inter; |
3617 |
return 1; |
3618 |
} |
3619 |
|
3620 |
/*
|
3621 |
* [sector_num, nb_sectors] is unallocated on top but intermediate
|
3622 |
* might have
|
3623 |
*
|
3624 |
* [sector_num+x, nr_sectors] allocated.
|
3625 |
*/
|
3626 |
if (n > pnum_inter &&
|
3627 |
(intermediate == top || |
3628 |
sector_num + pnum_inter < intermediate->total_sectors)) { |
3629 |
n = pnum_inter; |
3630 |
} |
3631 |
|
3632 |
intermediate = intermediate->backing_hd; |
3633 |
} |
3634 |
|
3635 |
*pnum = n; |
3636 |
return 0; |
3637 |
} |
3638 |
|
3639 |
const char *bdrv_get_encrypted_filename(BlockDriverState *bs) |
3640 |
{ |
3641 |
if (bs->backing_hd && bs->backing_hd->encrypted)
|
3642 |
return bs->backing_file;
|
3643 |
else if (bs->encrypted) |
3644 |
return bs->filename;
|
3645 |
else
|
3646 |
return NULL; |
3647 |
} |
3648 |
|
3649 |
void bdrv_get_backing_filename(BlockDriverState *bs,
|
3650 |
char *filename, int filename_size) |
3651 |
{ |
3652 |
pstrcpy(filename, filename_size, bs->backing_file); |
3653 |
} |
3654 |
|
3655 |
int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
|
3656 |
const uint8_t *buf, int nb_sectors) |
3657 |
{ |
3658 |
BlockDriver *drv = bs->drv; |
3659 |
if (!drv)
|
3660 |
return -ENOMEDIUM;
|
3661 |
if (!drv->bdrv_write_compressed)
|
3662 |
return -ENOTSUP;
|
3663 |
if (bdrv_check_request(bs, sector_num, nb_sectors))
|
3664 |
return -EIO;
|
3665 |
|
3666 |
assert(QLIST_EMPTY(&bs->dirty_bitmaps)); |
3667 |
|
3668 |
return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
|
3669 |
} |
3670 |
|
3671 |
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
3672 |
{ |
3673 |
BlockDriver *drv = bs->drv; |
3674 |
if (!drv)
|
3675 |
return -ENOMEDIUM;
|
3676 |
if (!drv->bdrv_get_info)
|
3677 |
return -ENOTSUP;
|
3678 |
memset(bdi, 0, sizeof(*bdi)); |
3679 |
return drv->bdrv_get_info(bs, bdi);
|
3680 |
} |
3681 |
|
3682 |
ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs) |
3683 |
{ |
3684 |
BlockDriver *drv = bs->drv; |
3685 |
if (drv && drv->bdrv_get_specific_info) {
|
3686 |
return drv->bdrv_get_specific_info(bs);
|
3687 |
} |
3688 |
return NULL; |
3689 |
} |
3690 |
|
3691 |
int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
3692 |
int64_t pos, int size)
|
3693 |
{ |
3694 |
QEMUIOVector qiov; |
3695 |
struct iovec iov = {
|
3696 |
.iov_base = (void *) buf,
|
3697 |
.iov_len = size, |
3698 |
}; |
3699 |
|
3700 |
qemu_iovec_init_external(&qiov, &iov, 1);
|
3701 |
return bdrv_writev_vmstate(bs, &qiov, pos);
|
3702 |
} |
3703 |
|
3704 |
int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
|
3705 |
{ |
3706 |
BlockDriver *drv = bs->drv; |
3707 |
|
3708 |
if (!drv) {
|
3709 |
return -ENOMEDIUM;
|
3710 |
} else if (drv->bdrv_save_vmstate) { |
3711 |
return drv->bdrv_save_vmstate(bs, qiov, pos);
|
3712 |
} else if (bs->file) { |
3713 |
return bdrv_writev_vmstate(bs->file, qiov, pos);
|
3714 |
} |
3715 |
|
3716 |
return -ENOTSUP;
|
3717 |
} |
3718 |
|
3719 |
int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
|
3720 |
int64_t pos, int size)
|
3721 |
{ |
3722 |
BlockDriver *drv = bs->drv; |
3723 |
if (!drv)
|
3724 |
return -ENOMEDIUM;
|
3725 |
if (drv->bdrv_load_vmstate)
|
3726 |
return drv->bdrv_load_vmstate(bs, buf, pos, size);
|
3727 |
if (bs->file)
|
3728 |
return bdrv_load_vmstate(bs->file, buf, pos, size);
|
3729 |
return -ENOTSUP;
|
3730 |
} |
3731 |
|
3732 |
void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event)
|
3733 |
{ |
3734 |
if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
|
3735 |
return;
|
3736 |
} |
3737 |
|
3738 |
bs->drv->bdrv_debug_event(bs, event); |
3739 |
} |
3740 |
|
3741 |
int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, |
3742 |
const char *tag) |
3743 |
{ |
3744 |
while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
|
3745 |
bs = bs->file; |
3746 |
} |
3747 |
|
3748 |
if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
|
3749 |
return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
|
3750 |
} |
3751 |
|
3752 |
return -ENOTSUP;
|
3753 |
} |
3754 |
|
3755 |
int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) |
3756 |
{ |
3757 |
while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
|
3758 |
bs = bs->file; |
3759 |
} |
3760 |
|
3761 |
if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
|
3762 |
return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
|
3763 |
} |
3764 |
|
3765 |
return -ENOTSUP;
|
3766 |
} |
3767 |
|
3768 |
int bdrv_debug_resume(BlockDriverState *bs, const char *tag) |
3769 |
{ |
3770 |
while (bs && bs->drv && !bs->drv->bdrv_debug_resume) {
|
3771 |
bs = bs->file; |
3772 |
} |
3773 |
|
3774 |
if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
|
3775 |
return bs->drv->bdrv_debug_resume(bs, tag);
|
3776 |
} |
3777 |
|
3778 |
return -ENOTSUP;
|
3779 |
} |
3780 |
|
3781 |
bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) |
3782 |
{ |
3783 |
while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
|
3784 |
bs = bs->file; |
3785 |
} |
3786 |
|
3787 |
if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
|
3788 |
return bs->drv->bdrv_debug_is_suspended(bs, tag);
|
3789 |
} |
3790 |
|
3791 |
return false; |
3792 |
} |
3793 |
|
3794 |
int bdrv_is_snapshot(BlockDriverState *bs)
|
3795 |
{ |
3796 |
return !!(bs->open_flags & BDRV_O_SNAPSHOT);
|
3797 |
} |
3798 |
|
3799 |
/* backing_file can either be relative, or absolute, or a protocol. If it is
|
3800 |
* relative, it must be relative to the chain. So, passing in bs->filename
|
3801 |
* from a BDS as backing_file should not be done, as that may be relative to
|
3802 |
* the CWD rather than the chain. */
|
3803 |
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, |
3804 |
const char *backing_file) |
3805 |
{ |
3806 |
char *filename_full = NULL; |
3807 |
char *backing_file_full = NULL; |
3808 |
char *filename_tmp = NULL; |
3809 |
int is_protocol = 0; |
3810 |
BlockDriverState *curr_bs = NULL;
|
3811 |
BlockDriverState *retval = NULL;
|
3812 |
|
3813 |
if (!bs || !bs->drv || !backing_file) {
|
3814 |
return NULL; |
3815 |
} |
3816 |
|
3817 |
filename_full = g_malloc(PATH_MAX); |
3818 |
backing_file_full = g_malloc(PATH_MAX); |
3819 |
filename_tmp = g_malloc(PATH_MAX); |
3820 |
|
3821 |
is_protocol = path_has_protocol(backing_file); |
3822 |
|
3823 |
for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
|
3824 |
|
3825 |
/* If either of the filename paths is actually a protocol, then
|
3826 |
* compare unmodified paths; otherwise make paths relative */
|
3827 |
if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
|
3828 |
if (strcmp(backing_file, curr_bs->backing_file) == 0) { |
3829 |
retval = curr_bs->backing_hd; |
3830 |
break;
|
3831 |
} |
3832 |
} else {
|
3833 |
/* If not an absolute filename path, make it relative to the current
|
3834 |
* image's filename path */
|
3835 |
path_combine(filename_tmp, PATH_MAX, curr_bs->filename, |
3836 |
backing_file); |
3837 |
|
3838 |
/* We are going to compare absolute pathnames */
|
3839 |
if (!realpath(filename_tmp, filename_full)) {
|
3840 |
continue;
|
3841 |
} |
3842 |
|
3843 |
/* We need to make sure the backing filename we are comparing against
|
3844 |
* is relative to the current image filename (or absolute) */
|
3845 |
path_combine(filename_tmp, PATH_MAX, curr_bs->filename, |
3846 |
curr_bs->backing_file); |
3847 |
|
3848 |
if (!realpath(filename_tmp, backing_file_full)) {
|
3849 |
continue;
|
3850 |
} |
3851 |
|
3852 |
if (strcmp(backing_file_full, filename_full) == 0) { |
3853 |
retval = curr_bs->backing_hd; |
3854 |
break;
|
3855 |
} |
3856 |
} |
3857 |
} |
3858 |
|
3859 |
g_free(filename_full); |
3860 |
g_free(backing_file_full); |
3861 |
g_free(filename_tmp); |
3862 |
return retval;
|
3863 |
} |
3864 |
|
3865 |
int bdrv_get_backing_file_depth(BlockDriverState *bs)
|
3866 |
{ |
3867 |
if (!bs->drv) {
|
3868 |
return 0; |
3869 |
} |
3870 |
|
3871 |
if (!bs->backing_hd) {
|
3872 |
return 0; |
3873 |
} |
3874 |
|
3875 |
return 1 + bdrv_get_backing_file_depth(bs->backing_hd); |
3876 |
} |
3877 |
|
3878 |
BlockDriverState *bdrv_find_base(BlockDriverState *bs) |
3879 |
{ |
3880 |
BlockDriverState *curr_bs = NULL;
|
3881 |
|
3882 |
if (!bs) {
|
3883 |
return NULL; |
3884 |
} |
3885 |
|
3886 |
curr_bs = bs; |
3887 |
|
3888 |
while (curr_bs->backing_hd) {
|
3889 |
curr_bs = curr_bs->backing_hd; |
3890 |
} |
3891 |
return curr_bs;
|
3892 |
} |
3893 |
|
3894 |
/**************************************************************/
|
3895 |
/* async I/Os */
|
3896 |
|
3897 |
BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, |
3898 |
QEMUIOVector *qiov, int nb_sectors,
|
3899 |
BlockDriverCompletionFunc *cb, void *opaque)
|
3900 |
{ |
3901 |
trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); |
3902 |
|
3903 |
return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, |
3904 |
cb, opaque, false);
|
3905 |
} |
3906 |
|
3907 |
BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, |
3908 |
QEMUIOVector *qiov, int nb_sectors,
|
3909 |
BlockDriverCompletionFunc *cb, void *opaque)
|
3910 |
{ |
3911 |
trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); |
3912 |
|
3913 |
return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, |
3914 |
cb, opaque, true);
|
3915 |
} |
3916 |
|
3917 |
BlockDriverAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, |
3918 |
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags,
|
3919 |
BlockDriverCompletionFunc *cb, void *opaque)
|
3920 |
{ |
3921 |
trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque); |
3922 |
|
3923 |
return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors, |
3924 |
BDRV_REQ_ZERO_WRITE | flags, |
3925 |
cb, opaque, true);
|
3926 |
} |
3927 |
|
3928 |
|
3929 |
typedef struct MultiwriteCB { |
3930 |
int error;
|
3931 |
int num_requests;
|
3932 |
int num_callbacks;
|
3933 |
struct {
|
3934 |
BlockDriverCompletionFunc *cb; |
3935 |
void *opaque;
|
3936 |
QEMUIOVector *free_qiov; |
3937 |
} callbacks[]; |
3938 |
} MultiwriteCB; |
3939 |
|
3940 |
static void multiwrite_user_cb(MultiwriteCB *mcb) |
3941 |
{ |
3942 |
int i;
|
3943 |
|
3944 |
for (i = 0; i < mcb->num_callbacks; i++) { |
3945 |
mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); |
3946 |
if (mcb->callbacks[i].free_qiov) {
|
3947 |
qemu_iovec_destroy(mcb->callbacks[i].free_qiov); |
3948 |
} |
3949 |
g_free(mcb->callbacks[i].free_qiov); |
3950 |
} |
3951 |
} |
3952 |
|
3953 |
static void multiwrite_cb(void *opaque, int ret) |
3954 |
{ |
3955 |
MultiwriteCB *mcb = opaque; |
3956 |
|
3957 |
trace_multiwrite_cb(mcb, ret); |
3958 |
|
3959 |
if (ret < 0 && !mcb->error) { |
3960 |
mcb->error = ret; |
3961 |
} |
3962 |
|
3963 |
mcb->num_requests--; |
3964 |
if (mcb->num_requests == 0) { |
3965 |
multiwrite_user_cb(mcb); |
3966 |
g_free(mcb); |
3967 |
} |
3968 |
} |
3969 |
|
3970 |
static int multiwrite_req_compare(const void *a, const void *b) |
3971 |
{ |
3972 |
const BlockRequest *req1 = a, *req2 = b;
|
3973 |
|
3974 |
/*
|
3975 |
* Note that we can't simply subtract req2->sector from req1->sector
|
3976 |
* here as that could overflow the return value.
|
3977 |
*/
|
3978 |
if (req1->sector > req2->sector) {
|
3979 |
return 1; |
3980 |
} else if (req1->sector < req2->sector) { |
3981 |
return -1; |
3982 |
} else {
|
3983 |
return 0; |
3984 |
} |
3985 |
} |
3986 |
|
3987 |
/*
|
3988 |
* Takes a bunch of requests and tries to merge them. Returns the number of
|
3989 |
* requests that remain after merging.
|
3990 |
*/
|
3991 |
static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, |
3992 |
int num_reqs, MultiwriteCB *mcb)
|
3993 |
{ |
3994 |
int i, outidx;
|
3995 |
|
3996 |
// Sort requests by start sector
|
3997 |
qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
|
3998 |
|
3999 |
// Check if adjacent requests touch the same clusters. If so, combine them,
|
4000 |
// filling up gaps with zero sectors.
|
4001 |
outidx = 0;
|
4002 |
for (i = 1; i < num_reqs; i++) { |
4003 |
int merge = 0; |
4004 |
int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; |
4005 |
|
4006 |
// Handle exactly sequential writes and overlapping writes.
|
4007 |
if (reqs[i].sector <= oldreq_last) {
|
4008 |
merge = 1;
|
4009 |
} |
4010 |
|
4011 |
if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { |
4012 |
merge = 0;
|
4013 |
} |
4014 |
|
4015 |
if (merge) {
|
4016 |
size_t size; |
4017 |
QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
|
4018 |
qemu_iovec_init(qiov, |
4019 |
reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
|
4020 |
|
4021 |
// Add the first request to the merged one. If the requests are
|
4022 |
// overlapping, drop the last sectors of the first request.
|
4023 |
size = (reqs[i].sector - reqs[outidx].sector) << 9;
|
4024 |
qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size);
|
4025 |
|
4026 |
// We should need to add any zeros between the two requests
|
4027 |
assert (reqs[i].sector <= oldreq_last); |
4028 |
|
4029 |
// Add the second request
|
4030 |
qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size);
|
4031 |
|
4032 |
reqs[outidx].nb_sectors = qiov->size >> 9;
|
4033 |
reqs[outidx].qiov = qiov; |
4034 |
|
4035 |
mcb->callbacks[i].free_qiov = reqs[outidx].qiov; |
4036 |
} else {
|
4037 |
outidx++; |
4038 |
reqs[outidx].sector = reqs[i].sector; |
4039 |
reqs[outidx].nb_sectors = reqs[i].nb_sectors; |
4040 |
reqs[outidx].qiov = reqs[i].qiov; |
4041 |
} |
4042 |
} |
4043 |
|
4044 |
return outidx + 1; |
4045 |
} |
4046 |
|
4047 |
/*
|
4048 |
* Submit multiple AIO write requests at once.
|
4049 |
*
|
4050 |
* On success, the function returns 0 and all requests in the reqs array have
|
4051 |
* been submitted. In error case this function returns -1, and any of the
|
4052 |
* requests may or may not be submitted yet. In particular, this means that the
|
4053 |
* callback will be called for some of the requests, for others it won't. The
|
4054 |
* caller must check the error field of the BlockRequest to wait for the right
|
4055 |
* callbacks (if error != 0, no callback will be called).
|
4056 |
*
|
4057 |
* The implementation may modify the contents of the reqs array, e.g. to merge
|
4058 |
* requests. However, the fields opaque and error are left unmodified as they
|
4059 |
* are used to signal failure for a single request to the caller.
|
4060 |
*/
|
4061 |
int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) |
4062 |
{ |
4063 |
MultiwriteCB *mcb; |
4064 |
int i;
|
4065 |
|
4066 |
/* don't submit writes if we don't have a medium */
|
4067 |
if (bs->drv == NULL) { |
4068 |
for (i = 0; i < num_reqs; i++) { |
4069 |
reqs[i].error = -ENOMEDIUM; |
4070 |
} |
4071 |
return -1; |
4072 |
} |
4073 |
|
4074 |
if (num_reqs == 0) { |
4075 |
return 0; |
4076 |
} |
4077 |
|
4078 |
// Create MultiwriteCB structure
|
4079 |
mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); |
4080 |
mcb->num_requests = 0;
|
4081 |
mcb->num_callbacks = num_reqs; |
4082 |
|
4083 |
for (i = 0; i < num_reqs; i++) { |
4084 |
mcb->callbacks[i].cb = reqs[i].cb; |
4085 |
mcb->callbacks[i].opaque = reqs[i].opaque; |
4086 |
} |
4087 |
|
4088 |
// Check for mergable requests
|
4089 |
num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); |
4090 |
|
4091 |
trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); |
4092 |
|
4093 |
/* Run the aio requests. */
|
4094 |
mcb->num_requests = num_reqs; |
4095 |
for (i = 0; i < num_reqs; i++) { |
4096 |
bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov, |
4097 |
reqs[i].nb_sectors, reqs[i].flags, |
4098 |
multiwrite_cb, mcb, |
4099 |
true);
|
4100 |
} |
4101 |
|
4102 |
return 0; |
4103 |
} |
4104 |
|
4105 |
void bdrv_aio_cancel(BlockDriverAIOCB *acb)
|
4106 |
{ |
4107 |
acb->aiocb_info->cancel(acb); |
4108 |
} |
4109 |
|
4110 |
/**************************************************************/
|
4111 |
/* async block device emulation */
|
4112 |
|
4113 |
typedef struct BlockDriverAIOCBSync { |
4114 |
BlockDriverAIOCB common; |
4115 |
QEMUBH *bh; |
4116 |
int ret;
|
4117 |
/* vector translation state */
|
4118 |
QEMUIOVector *qiov; |
4119 |
uint8_t *bounce; |
4120 |
int is_write;
|
4121 |
} BlockDriverAIOCBSync; |
4122 |
|
4123 |
static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) |
4124 |
{ |
4125 |
BlockDriverAIOCBSync *acb = |
4126 |
container_of(blockacb, BlockDriverAIOCBSync, common); |
4127 |
qemu_bh_delete(acb->bh); |
4128 |
acb->bh = NULL;
|
4129 |
qemu_aio_release(acb); |
4130 |
} |
4131 |
|
4132 |
static const AIOCBInfo bdrv_em_aiocb_info = { |
4133 |
.aiocb_size = sizeof(BlockDriverAIOCBSync),
|
4134 |
.cancel = bdrv_aio_cancel_em, |
4135 |
}; |
4136 |
|
4137 |
static void bdrv_aio_bh_cb(void *opaque) |
4138 |
{ |
4139 |
BlockDriverAIOCBSync *acb = opaque; |
4140 |
|
4141 |
if (!acb->is_write)
|
4142 |
qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);
|
4143 |
qemu_vfree(acb->bounce); |
4144 |
acb->common.cb(acb->common.opaque, acb->ret); |
4145 |
qemu_bh_delete(acb->bh); |
4146 |
acb->bh = NULL;
|
4147 |
qemu_aio_release(acb); |
4148 |
} |
4149 |
|
4150 |
static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
|
4151 |
int64_t sector_num, |
4152 |
QEMUIOVector *qiov, |
4153 |
int nb_sectors,
|
4154 |
BlockDriverCompletionFunc *cb, |
4155 |
void *opaque,
|
4156 |
int is_write)
|
4157 |
|
4158 |
{ |
4159 |
BlockDriverAIOCBSync *acb; |
4160 |
|
4161 |
acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque); |
4162 |
acb->is_write = is_write; |
4163 |
acb->qiov = qiov; |
4164 |
acb->bounce = qemu_blockalign(bs, qiov->size); |
4165 |
acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); |
4166 |
|
4167 |
if (is_write) {
|
4168 |
qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);
|
4169 |
acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); |
4170 |
} else {
|
4171 |
acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); |
4172 |
} |
4173 |
|
4174 |
qemu_bh_schedule(acb->bh); |
4175 |
|
4176 |
return &acb->common;
|
4177 |
} |
4178 |
|
4179 |
static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
|
4180 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
4181 |
BlockDriverCompletionFunc *cb, void *opaque)
|
4182 |
{ |
4183 |
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); |
4184 |
} |
4185 |
|
4186 |
static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
|
4187 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
4188 |
BlockDriverCompletionFunc *cb, void *opaque)
|
4189 |
{ |
4190 |
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); |
4191 |
} |
4192 |
|
4193 |
|
4194 |
typedef struct BlockDriverAIOCBCoroutine { |
4195 |
BlockDriverAIOCB common; |
4196 |
BlockRequest req; |
4197 |
bool is_write;
|
4198 |
bool *done;
|
4199 |
QEMUBH* bh; |
4200 |
} BlockDriverAIOCBCoroutine; |
4201 |
|
4202 |
static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb) |
4203 |
{ |
4204 |
BlockDriverAIOCBCoroutine *acb = |
4205 |
container_of(blockacb, BlockDriverAIOCBCoroutine, common); |
4206 |
bool done = false; |
4207 |
|
4208 |
acb->done = &done; |
4209 |
while (!done) {
|
4210 |
qemu_aio_wait(); |
4211 |
} |
4212 |
} |
4213 |
|
4214 |
static const AIOCBInfo bdrv_em_co_aiocb_info = { |
4215 |
.aiocb_size = sizeof(BlockDriverAIOCBCoroutine),
|
4216 |
.cancel = bdrv_aio_co_cancel_em, |
4217 |
}; |
4218 |
|
4219 |
static void bdrv_co_em_bh(void *opaque) |
4220 |
{ |
4221 |
BlockDriverAIOCBCoroutine *acb = opaque; |
4222 |
|
4223 |
acb->common.cb(acb->common.opaque, acb->req.error); |
4224 |
|
4225 |
if (acb->done) {
|
4226 |
*acb->done = true;
|
4227 |
} |
4228 |
|
4229 |
qemu_bh_delete(acb->bh); |
4230 |
qemu_aio_release(acb); |
4231 |
} |
4232 |
|
4233 |
/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
|
4234 |
static void coroutine_fn bdrv_co_do_rw(void *opaque) |
4235 |
{ |
4236 |
BlockDriverAIOCBCoroutine *acb = opaque; |
4237 |
BlockDriverState *bs = acb->common.bs; |
4238 |
|
4239 |
if (!acb->is_write) {
|
4240 |
acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, |
4241 |
acb->req.nb_sectors, acb->req.qiov, acb->req.flags); |
4242 |
} else {
|
4243 |
acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, |
4244 |
acb->req.nb_sectors, acb->req.qiov, acb->req.flags); |
4245 |
} |
4246 |
|
4247 |
acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); |
4248 |
qemu_bh_schedule(acb->bh); |
4249 |
} |
4250 |
|
4251 |
static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
|
4252 |
int64_t sector_num, |
4253 |
QEMUIOVector *qiov, |
4254 |
int nb_sectors,
|
4255 |
BdrvRequestFlags flags, |
4256 |
BlockDriverCompletionFunc *cb, |
4257 |
void *opaque,
|
4258 |
bool is_write)
|
4259 |
{ |
4260 |
Coroutine *co; |
4261 |
BlockDriverAIOCBCoroutine *acb; |
4262 |
|
4263 |
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); |
4264 |
acb->req.sector = sector_num; |
4265 |
acb->req.nb_sectors = nb_sectors; |
4266 |
acb->req.qiov = qiov; |
4267 |
acb->req.flags = flags; |
4268 |
acb->is_write = is_write; |
4269 |
acb->done = NULL;
|
4270 |
|
4271 |
co = qemu_coroutine_create(bdrv_co_do_rw); |
4272 |
qemu_coroutine_enter(co, acb); |
4273 |
|
4274 |
return &acb->common;
|
4275 |
} |
4276 |
|
4277 |
static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) |
4278 |
{ |
4279 |
BlockDriverAIOCBCoroutine *acb = opaque; |
4280 |
BlockDriverState *bs = acb->common.bs; |
4281 |
|
4282 |
acb->req.error = bdrv_co_flush(bs); |
4283 |
acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); |
4284 |
qemu_bh_schedule(acb->bh); |
4285 |
} |
4286 |
|
4287 |
BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, |
4288 |
BlockDriverCompletionFunc *cb, void *opaque)
|
4289 |
{ |
4290 |
trace_bdrv_aio_flush(bs, opaque); |
4291 |
|
4292 |
Coroutine *co; |
4293 |
BlockDriverAIOCBCoroutine *acb; |
4294 |
|
4295 |
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); |
4296 |
acb->done = NULL;
|
4297 |
|
4298 |
co = qemu_coroutine_create(bdrv_aio_flush_co_entry); |
4299 |
qemu_coroutine_enter(co, acb); |
4300 |
|
4301 |
return &acb->common;
|
4302 |
} |
4303 |
|
4304 |
static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) |
4305 |
{ |
4306 |
BlockDriverAIOCBCoroutine *acb = opaque; |
4307 |
BlockDriverState *bs = acb->common.bs; |
4308 |
|
4309 |
acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); |
4310 |
acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); |
4311 |
qemu_bh_schedule(acb->bh); |
4312 |
} |
4313 |
|
4314 |
BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs, |
4315 |
int64_t sector_num, int nb_sectors,
|
4316 |
BlockDriverCompletionFunc *cb, void *opaque)
|
4317 |
{ |
4318 |
Coroutine *co; |
4319 |
BlockDriverAIOCBCoroutine *acb; |
4320 |
|
4321 |
trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); |
4322 |
|
4323 |
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); |
4324 |
acb->req.sector = sector_num; |
4325 |
acb->req.nb_sectors = nb_sectors; |
4326 |
acb->done = NULL;
|
4327 |
co = qemu_coroutine_create(bdrv_aio_discard_co_entry); |
4328 |
qemu_coroutine_enter(co, acb); |
4329 |
|
4330 |
return &acb->common;
|
4331 |
} |
4332 |
|
4333 |
void bdrv_init(void) |
4334 |
{ |
4335 |
module_call_init(MODULE_INIT_BLOCK); |
4336 |
} |
4337 |
|
4338 |
void bdrv_init_with_whitelist(void) |
4339 |
{ |
4340 |
use_bdrv_whitelist = 1;
|
4341 |
bdrv_init(); |
4342 |
} |
4343 |
|
4344 |
void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs, |
4345 |
BlockDriverCompletionFunc *cb, void *opaque)
|
4346 |
{ |
4347 |
BlockDriverAIOCB *acb; |
4348 |
|
4349 |
acb = g_slice_alloc(aiocb_info->aiocb_size); |
4350 |
acb->aiocb_info = aiocb_info; |
4351 |
acb->bs = bs; |
4352 |
acb->cb = cb; |
4353 |
acb->opaque = opaque; |
4354 |
return acb;
|
4355 |
} |
4356 |
|
4357 |
void qemu_aio_release(void *p) |
4358 |
{ |
4359 |
BlockDriverAIOCB *acb = p; |
4360 |
g_slice_free1(acb->aiocb_info->aiocb_size, acb); |
4361 |
} |
4362 |
|
4363 |
/**************************************************************/
|
4364 |
/* Coroutine block device emulation */
|
4365 |
|
4366 |
typedef struct CoroutineIOCompletion { |
4367 |
Coroutine *coroutine; |
4368 |
int ret;
|
4369 |
} CoroutineIOCompletion; |
4370 |
|
4371 |
static void bdrv_co_io_em_complete(void *opaque, int ret) |
4372 |
{ |
4373 |
CoroutineIOCompletion *co = opaque; |
4374 |
|
4375 |
co->ret = ret; |
4376 |
qemu_coroutine_enter(co->coroutine, NULL);
|
4377 |
} |
4378 |
|
4379 |
static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, |
4380 |
int nb_sectors, QEMUIOVector *iov,
|
4381 |
bool is_write)
|
4382 |
{ |
4383 |
CoroutineIOCompletion co = { |
4384 |
.coroutine = qemu_coroutine_self(), |
4385 |
}; |
4386 |
BlockDriverAIOCB *acb; |
4387 |
|
4388 |
if (is_write) {
|
4389 |
acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, |
4390 |
bdrv_co_io_em_complete, &co); |
4391 |
} else {
|
4392 |
acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, |
4393 |
bdrv_co_io_em_complete, &co); |
4394 |
} |
4395 |
|
4396 |
trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); |
4397 |
if (!acb) {
|
4398 |
return -EIO;
|
4399 |
} |
4400 |
qemu_coroutine_yield(); |
4401 |
|
4402 |
return co.ret;
|
4403 |
} |
4404 |
|
4405 |
static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, |
4406 |
int64_t sector_num, int nb_sectors,
|
4407 |
QEMUIOVector *iov) |
4408 |
{ |
4409 |
return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); |
4410 |
} |
4411 |
|
4412 |
static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, |
4413 |
int64_t sector_num, int nb_sectors,
|
4414 |
QEMUIOVector *iov) |
4415 |
{ |
4416 |
return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); |
4417 |
} |
4418 |
|
4419 |
static void coroutine_fn bdrv_flush_co_entry(void *opaque) |
4420 |
{ |
4421 |
RwCo *rwco = opaque; |
4422 |
|
4423 |
rwco->ret = bdrv_co_flush(rwco->bs); |
4424 |
} |
4425 |
|
4426 |
int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
|
4427 |
{ |
4428 |
int ret;
|
4429 |
|
4430 |
if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
|
4431 |
return 0; |
4432 |
} |
4433 |
|
4434 |
/* Write back cached data to the OS even with cache=unsafe */
|
4435 |
BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); |
4436 |
if (bs->drv->bdrv_co_flush_to_os) {
|
4437 |
ret = bs->drv->bdrv_co_flush_to_os(bs); |
4438 |
if (ret < 0) { |
4439 |
return ret;
|
4440 |
} |
4441 |
} |
4442 |
|
4443 |
/* But don't actually force it to the disk with cache=unsafe */
|
4444 |
if (bs->open_flags & BDRV_O_NO_FLUSH) {
|
4445 |
goto flush_parent;
|
4446 |
} |
4447 |
|
4448 |
BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); |
4449 |
if (bs->drv->bdrv_co_flush_to_disk) {
|
4450 |
ret = bs->drv->bdrv_co_flush_to_disk(bs); |
4451 |
} else if (bs->drv->bdrv_aio_flush) { |
4452 |
BlockDriverAIOCB *acb; |
4453 |
CoroutineIOCompletion co = { |
4454 |
.coroutine = qemu_coroutine_self(), |
4455 |
}; |
4456 |
|
4457 |
acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); |
4458 |
if (acb == NULL) { |
4459 |
ret = -EIO; |
4460 |
} else {
|
4461 |
qemu_coroutine_yield(); |
4462 |
ret = co.ret; |
4463 |
} |
4464 |
} else {
|
4465 |
/*
|
4466 |
* Some block drivers always operate in either writethrough or unsafe
|
4467 |
* mode and don't support bdrv_flush therefore. Usually qemu doesn't
|
4468 |
* know how the server works (because the behaviour is hardcoded or
|
4469 |
* depends on server-side configuration), so we can't ensure that
|
4470 |
* everything is safe on disk. Returning an error doesn't work because
|
4471 |
* that would break guests even if the server operates in writethrough
|
4472 |
* mode.
|
4473 |
*
|
4474 |
* Let's hope the user knows what he's doing.
|
4475 |
*/
|
4476 |
ret = 0;
|
4477 |
} |
4478 |
if (ret < 0) { |
4479 |
return ret;
|
4480 |
} |
4481 |
|
4482 |
/* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH
|
4483 |
* in the case of cache=unsafe, so there are no useless flushes.
|
4484 |
*/
|
4485 |
flush_parent:
|
4486 |
return bdrv_co_flush(bs->file);
|
4487 |
} |
4488 |
|
4489 |
void bdrv_invalidate_cache(BlockDriverState *bs)
|
4490 |
{ |
4491 |
if (bs->drv && bs->drv->bdrv_invalidate_cache) {
|
4492 |
bs->drv->bdrv_invalidate_cache(bs); |
4493 |
} |
4494 |
} |
4495 |
|
4496 |
void bdrv_invalidate_cache_all(void) |
4497 |
{ |
4498 |
BlockDriverState *bs; |
4499 |
|
4500 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
4501 |
bdrv_invalidate_cache(bs); |
4502 |
} |
4503 |
} |
4504 |
|
4505 |
void bdrv_clear_incoming_migration_all(void) |
4506 |
{ |
4507 |
BlockDriverState *bs; |
4508 |
|
4509 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
4510 |
bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); |
4511 |
} |
4512 |
} |
4513 |
|
4514 |
int bdrv_flush(BlockDriverState *bs)
|
4515 |
{ |
4516 |
Coroutine *co; |
4517 |
RwCo rwco = { |
4518 |
.bs = bs, |
4519 |
.ret = NOT_DONE, |
4520 |
}; |
4521 |
|
4522 |
if (qemu_in_coroutine()) {
|
4523 |
/* Fast-path if already in coroutine context */
|
4524 |
bdrv_flush_co_entry(&rwco); |
4525 |
} else {
|
4526 |
co = qemu_coroutine_create(bdrv_flush_co_entry); |
4527 |
qemu_coroutine_enter(co, &rwco); |
4528 |
while (rwco.ret == NOT_DONE) {
|
4529 |
qemu_aio_wait(); |
4530 |
} |
4531 |
} |
4532 |
|
4533 |
return rwco.ret;
|
4534 |
} |
4535 |
|
4536 |
static void coroutine_fn bdrv_discard_co_entry(void *opaque) |
4537 |
{ |
4538 |
RwCo *rwco = opaque; |
4539 |
|
4540 |
rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); |
4541 |
} |
4542 |
|
4543 |
/* if no limit is specified in the BlockLimits use a default
|
4544 |
* of 32768 512-byte sectors (16 MiB) per request.
|
4545 |
*/
|
4546 |
#define MAX_DISCARD_DEFAULT 32768 |
4547 |
|
4548 |
int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
|
4549 |
int nb_sectors)
|
4550 |
{ |
4551 |
int max_discard;
|
4552 |
|
4553 |
if (!bs->drv) {
|
4554 |
return -ENOMEDIUM;
|
4555 |
} else if (bdrv_check_request(bs, sector_num, nb_sectors)) { |
4556 |
return -EIO;
|
4557 |
} else if (bs->read_only) { |
4558 |
return -EROFS;
|
4559 |
} |
4560 |
|
4561 |
bdrv_reset_dirty(bs, sector_num, nb_sectors); |
4562 |
|
4563 |
/* Do nothing if disabled. */
|
4564 |
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
4565 |
return 0; |
4566 |
} |
4567 |
|
4568 |
if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) {
|
4569 |
return 0; |
4570 |
} |
4571 |
|
4572 |
max_discard = bs->bl.max_discard ? bs->bl.max_discard : MAX_DISCARD_DEFAULT; |
4573 |
while (nb_sectors > 0) { |
4574 |
int ret;
|
4575 |
int num = nb_sectors;
|
4576 |
|
4577 |
/* align request */
|
4578 |
if (bs->bl.discard_alignment &&
|
4579 |
num >= bs->bl.discard_alignment && |
4580 |
sector_num % bs->bl.discard_alignment) { |
4581 |
if (num > bs->bl.discard_alignment) {
|
4582 |
num = bs->bl.discard_alignment; |
4583 |
} |
4584 |
num -= sector_num % bs->bl.discard_alignment; |
4585 |
} |
4586 |
|
4587 |
/* limit request size */
|
4588 |
if (num > max_discard) {
|
4589 |
num = max_discard; |
4590 |
} |
4591 |
|
4592 |
if (bs->drv->bdrv_co_discard) {
|
4593 |
ret = bs->drv->bdrv_co_discard(bs, sector_num, num); |
4594 |
} else {
|
4595 |
BlockDriverAIOCB *acb; |
4596 |
CoroutineIOCompletion co = { |
4597 |
.coroutine = qemu_coroutine_self(), |
4598 |
}; |
4599 |
|
4600 |
acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, |
4601 |
bdrv_co_io_em_complete, &co); |
4602 |
if (acb == NULL) { |
4603 |
return -EIO;
|
4604 |
} else {
|
4605 |
qemu_coroutine_yield(); |
4606 |
ret = co.ret; |
4607 |
} |
4608 |
} |
4609 |
if (ret && ret != -ENOTSUP) {
|
4610 |
return ret;
|
4611 |
} |
4612 |
|
4613 |
sector_num += num; |
4614 |
nb_sectors -= num; |
4615 |
} |
4616 |
return 0; |
4617 |
} |
4618 |
|
4619 |
int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) |
4620 |
{ |
4621 |
Coroutine *co; |
4622 |
RwCo rwco = { |
4623 |
.bs = bs, |
4624 |
.sector_num = sector_num, |
4625 |
.nb_sectors = nb_sectors, |
4626 |
.ret = NOT_DONE, |
4627 |
}; |
4628 |
|
4629 |
if (qemu_in_coroutine()) {
|
4630 |
/* Fast-path if already in coroutine context */
|
4631 |
bdrv_discard_co_entry(&rwco); |
4632 |
} else {
|
4633 |
co = qemu_coroutine_create(bdrv_discard_co_entry); |
4634 |
qemu_coroutine_enter(co, &rwco); |
4635 |
while (rwco.ret == NOT_DONE) {
|
4636 |
qemu_aio_wait(); |
4637 |
} |
4638 |
} |
4639 |
|
4640 |
return rwco.ret;
|
4641 |
} |
4642 |
|
4643 |
/**************************************************************/
|
4644 |
/* removable device support */
|
4645 |
|
4646 |
/**
|
4647 |
* Return TRUE if the media is present
|
4648 |
*/
|
4649 |
int bdrv_is_inserted(BlockDriverState *bs)
|
4650 |
{ |
4651 |
BlockDriver *drv = bs->drv; |
4652 |
|
4653 |
if (!drv)
|
4654 |
return 0; |
4655 |
if (!drv->bdrv_is_inserted)
|
4656 |
return 1; |
4657 |
return drv->bdrv_is_inserted(bs);
|
4658 |
} |
4659 |
|
4660 |
/**
|
4661 |
* Return whether the media changed since the last call to this
|
4662 |
* function, or -ENOTSUP if we don't know. Most drivers don't know.
|
4663 |
*/
|
4664 |
int bdrv_media_changed(BlockDriverState *bs)
|
4665 |
{ |
4666 |
BlockDriver *drv = bs->drv; |
4667 |
|
4668 |
if (drv && drv->bdrv_media_changed) {
|
4669 |
return drv->bdrv_media_changed(bs);
|
4670 |
} |
4671 |
return -ENOTSUP;
|
4672 |
} |
4673 |
|
4674 |
/**
|
4675 |
* If eject_flag is TRUE, eject the media. Otherwise, close the tray
|
4676 |
*/
|
4677 |
void bdrv_eject(BlockDriverState *bs, bool eject_flag) |
4678 |
{ |
4679 |
BlockDriver *drv = bs->drv; |
4680 |
|
4681 |
if (drv && drv->bdrv_eject) {
|
4682 |
drv->bdrv_eject(bs, eject_flag); |
4683 |
} |
4684 |
|
4685 |
if (bs->device_name[0] != '\0') { |
4686 |
bdrv_emit_qmp_eject_event(bs, eject_flag); |
4687 |
} |
4688 |
} |
4689 |
|
4690 |
/**
|
4691 |
* Lock or unlock the media (if it is locked, the user won't be able
|
4692 |
* to eject it manually).
|
4693 |
*/
|
4694 |
void bdrv_lock_medium(BlockDriverState *bs, bool locked) |
4695 |
{ |
4696 |
BlockDriver *drv = bs->drv; |
4697 |
|
4698 |
trace_bdrv_lock_medium(bs, locked); |
4699 |
|
4700 |
if (drv && drv->bdrv_lock_medium) {
|
4701 |
drv->bdrv_lock_medium(bs, locked); |
4702 |
} |
4703 |
} |
4704 |
|
4705 |
/* needed for generic scsi interface */
|
4706 |
|
4707 |
int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) |
4708 |
{ |
4709 |
BlockDriver *drv = bs->drv; |
4710 |
|
4711 |
if (drv && drv->bdrv_ioctl)
|
4712 |
return drv->bdrv_ioctl(bs, req, buf);
|
4713 |
return -ENOTSUP;
|
4714 |
} |
4715 |
|
4716 |
BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, |
4717 |
unsigned long int req, void *buf, |
4718 |
BlockDriverCompletionFunc *cb, void *opaque)
|
4719 |
{ |
4720 |
BlockDriver *drv = bs->drv; |
4721 |
|
4722 |
if (drv && drv->bdrv_aio_ioctl)
|
4723 |
return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
|
4724 |
return NULL; |
4725 |
} |
4726 |
|
4727 |
void bdrv_set_buffer_alignment(BlockDriverState *bs, int align) |
4728 |
{ |
4729 |
bs->buffer_alignment = align; |
4730 |
} |
4731 |
|
4732 |
void *qemu_blockalign(BlockDriverState *bs, size_t size)
|
4733 |
{ |
4734 |
return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size); |
4735 |
} |
4736 |
|
4737 |
/*
|
4738 |
* Check if all memory in this vector is sector aligned.
|
4739 |
*/
|
4740 |
bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
|
4741 |
{ |
4742 |
int i;
|
4743 |
|
4744 |
for (i = 0; i < qiov->niov; i++) { |
4745 |
if ((uintptr_t) qiov->iov[i].iov_base % bs->buffer_alignment) {
|
4746 |
return false; |
4747 |
} |
4748 |
} |
4749 |
|
4750 |
return true; |
4751 |
} |
4752 |
|
4753 |
BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity)
|
4754 |
{ |
4755 |
int64_t bitmap_size; |
4756 |
BdrvDirtyBitmap *bitmap; |
4757 |
|
4758 |
assert((granularity & (granularity - 1)) == 0); |
4759 |
|
4760 |
granularity >>= BDRV_SECTOR_BITS; |
4761 |
assert(granularity); |
4762 |
bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS); |
4763 |
bitmap = g_malloc0(sizeof(BdrvDirtyBitmap));
|
4764 |
bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
|
4765 |
QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); |
4766 |
return bitmap;
|
4767 |
} |
4768 |
|
4769 |
void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
|
4770 |
{ |
4771 |
BdrvDirtyBitmap *bm, *next; |
4772 |
QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { |
4773 |
if (bm == bitmap) {
|
4774 |
QLIST_REMOVE(bitmap, list); |
4775 |
hbitmap_free(bitmap->bitmap); |
4776 |
g_free(bitmap); |
4777 |
return;
|
4778 |
} |
4779 |
} |
4780 |
} |
4781 |
|
4782 |
BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) |
4783 |
{ |
4784 |
BdrvDirtyBitmap *bm; |
4785 |
BlockDirtyInfoList *list = NULL;
|
4786 |
BlockDirtyInfoList **plist = &list; |
4787 |
|
4788 |
QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { |
4789 |
BlockDirtyInfo *info = g_malloc0(sizeof(BlockDirtyInfo));
|
4790 |
BlockDirtyInfoList *entry = g_malloc0(sizeof(BlockDirtyInfoList));
|
4791 |
info->count = bdrv_get_dirty_count(bs, bm); |
4792 |
info->granularity = |
4793 |
((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap)); |
4794 |
entry->value = info; |
4795 |
*plist = entry; |
4796 |
plist = &entry->next; |
4797 |
} |
4798 |
|
4799 |
return list;
|
4800 |
} |
4801 |
|
4802 |
int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector)
|
4803 |
{ |
4804 |
if (bitmap) {
|
4805 |
return hbitmap_get(bitmap->bitmap, sector);
|
4806 |
} else {
|
4807 |
return 0; |
4808 |
} |
4809 |
} |
4810 |
|
4811 |
void bdrv_dirty_iter_init(BlockDriverState *bs,
|
4812 |
BdrvDirtyBitmap *bitmap, HBitmapIter *hbi) |
4813 |
{ |
4814 |
hbitmap_iter_init(hbi, bitmap->bitmap, 0);
|
4815 |
} |
4816 |
|
4817 |
void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
|
4818 |
int nr_sectors)
|
4819 |
{ |
4820 |
BdrvDirtyBitmap *bitmap; |
4821 |
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { |
4822 |
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); |
4823 |
} |
4824 |
} |
4825 |
|
4826 |
void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors) |
4827 |
{ |
4828 |
BdrvDirtyBitmap *bitmap; |
4829 |
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { |
4830 |
hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); |
4831 |
} |
4832 |
} |
4833 |
|
4834 |
int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) |
4835 |
{ |
4836 |
return hbitmap_count(bitmap->bitmap);
|
4837 |
} |
4838 |
|
4839 |
/* Get a reference to bs */
|
4840 |
void bdrv_ref(BlockDriverState *bs)
|
4841 |
{ |
4842 |
bs->refcnt++; |
4843 |
} |
4844 |
|
4845 |
/* Release a previously grabbed reference to bs.
|
4846 |
* If after releasing, reference count is zero, the BlockDriverState is
|
4847 |
* deleted. */
|
4848 |
void bdrv_unref(BlockDriverState *bs)
|
4849 |
{ |
4850 |
assert(bs->refcnt > 0);
|
4851 |
if (--bs->refcnt == 0) { |
4852 |
bdrv_delete(bs); |
4853 |
} |
4854 |
} |
4855 |
|
4856 |
void bdrv_set_in_use(BlockDriverState *bs, int in_use) |
4857 |
{ |
4858 |
assert(bs->in_use != in_use); |
4859 |
bs->in_use = in_use; |
4860 |
} |
4861 |
|
4862 |
int bdrv_in_use(BlockDriverState *bs)
|
4863 |
{ |
4864 |
return bs->in_use;
|
4865 |
} |
4866 |
|
4867 |
void bdrv_iostatus_enable(BlockDriverState *bs)
|
4868 |
{ |
4869 |
bs->iostatus_enabled = true;
|
4870 |
bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
4871 |
} |
4872 |
|
4873 |
/* The I/O status is only enabled if the drive explicitly
|
4874 |
* enables it _and_ the VM is configured to stop on errors */
|
4875 |
bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) |
4876 |
{ |
4877 |
return (bs->iostatus_enabled &&
|
4878 |
(bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || |
4879 |
bs->on_write_error == BLOCKDEV_ON_ERROR_STOP || |
4880 |
bs->on_read_error == BLOCKDEV_ON_ERROR_STOP)); |
4881 |
} |
4882 |
|
4883 |
void bdrv_iostatus_disable(BlockDriverState *bs)
|
4884 |
{ |
4885 |
bs->iostatus_enabled = false;
|
4886 |
} |
4887 |
|
4888 |
void bdrv_iostatus_reset(BlockDriverState *bs)
|
4889 |
{ |
4890 |
if (bdrv_iostatus_is_enabled(bs)) {
|
4891 |
bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
4892 |
if (bs->job) {
|
4893 |
block_job_iostatus_reset(bs->job); |
4894 |
} |
4895 |
} |
4896 |
} |
4897 |
|
4898 |
void bdrv_iostatus_set_err(BlockDriverState *bs, int error) |
4899 |
{ |
4900 |
assert(bdrv_iostatus_is_enabled(bs)); |
4901 |
if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
|
4902 |
bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : |
4903 |
BLOCK_DEVICE_IO_STATUS_FAILED; |
4904 |
} |
4905 |
} |
4906 |
|
4907 |
void
|
4908 |
bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, |
4909 |
enum BlockAcctType type)
|
4910 |
{ |
4911 |
assert(type < BDRV_MAX_IOTYPE); |
4912 |
|
4913 |
cookie->bytes = bytes; |
4914 |
cookie->start_time_ns = get_clock(); |
4915 |
cookie->type = type; |
4916 |
} |
4917 |
|
4918 |
void
|
4919 |
bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie) |
4920 |
{ |
4921 |
assert(cookie->type < BDRV_MAX_IOTYPE); |
4922 |
|
4923 |
bs->nr_bytes[cookie->type] += cookie->bytes; |
4924 |
bs->nr_ops[cookie->type]++; |
4925 |
bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns; |
4926 |
} |
4927 |
|
4928 |
void bdrv_img_create(const char *filename, const char *fmt, |
4929 |
const char *base_filename, const char *base_fmt, |
4930 |
char *options, uint64_t img_size, int flags, |
4931 |
Error **errp, bool quiet)
|
4932 |
{ |
4933 |
QEMUOptionParameter *param = NULL, *create_options = NULL; |
4934 |
QEMUOptionParameter *backing_fmt, *backing_file, *size; |
4935 |
BlockDriver *drv, *proto_drv; |
4936 |
BlockDriver *backing_drv = NULL;
|
4937 |
Error *local_err = NULL;
|
4938 |
int ret = 0; |
4939 |
|
4940 |
/* Find driver and parse its options */
|
4941 |
drv = bdrv_find_format(fmt); |
4942 |
if (!drv) {
|
4943 |
error_setg(errp, "Unknown file format '%s'", fmt);
|
4944 |
return;
|
4945 |
} |
4946 |
|
4947 |
proto_drv = bdrv_find_protocol(filename, true);
|
4948 |
if (!proto_drv) {
|
4949 |
error_setg(errp, "Unknown protocol '%s'", filename);
|
4950 |
return;
|
4951 |
} |
4952 |
|
4953 |
create_options = append_option_parameters(create_options, |
4954 |
drv->create_options); |
4955 |
create_options = append_option_parameters(create_options, |
4956 |
proto_drv->create_options); |
4957 |
|
4958 |
/* Create parameter list with default values */
|
4959 |
param = parse_option_parameters("", create_options, param);
|
4960 |
|
4961 |
set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size); |
4962 |
|
4963 |
/* Parse -o options */
|
4964 |
if (options) {
|
4965 |
param = parse_option_parameters(options, create_options, param); |
4966 |
if (param == NULL) { |
4967 |
error_setg(errp, "Invalid options for file format '%s'.", fmt);
|
4968 |
goto out;
|
4969 |
} |
4970 |
} |
4971 |
|
4972 |
if (base_filename) {
|
4973 |
if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE,
|
4974 |
base_filename)) { |
4975 |
error_setg(errp, "Backing file not supported for file format '%s'",
|
4976 |
fmt); |
4977 |
goto out;
|
4978 |
} |
4979 |
} |
4980 |
|
4981 |
if (base_fmt) {
|
4982 |
if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) {
|
4983 |
error_setg(errp, "Backing file format not supported for file "
|
4984 |
"format '%s'", fmt);
|
4985 |
goto out;
|
4986 |
} |
4987 |
} |
4988 |
|
4989 |
backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE); |
4990 |
if (backing_file && backing_file->value.s) {
|
4991 |
if (!strcmp(filename, backing_file->value.s)) {
|
4992 |
error_setg(errp, "Error: Trying to create an image with the "
|
4993 |
"same filename as the backing file");
|
4994 |
goto out;
|
4995 |
} |
4996 |
} |
4997 |
|
4998 |
backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT); |
4999 |
if (backing_fmt && backing_fmt->value.s) {
|
5000 |
backing_drv = bdrv_find_format(backing_fmt->value.s); |
5001 |
if (!backing_drv) {
|
5002 |
error_setg(errp, "Unknown backing file format '%s'",
|
5003 |
backing_fmt->value.s); |
5004 |
goto out;
|
5005 |
} |
5006 |
} |
5007 |
|
5008 |
// The size for the image must always be specified, with one exception:
|
5009 |
// If we are using a backing file, we can obtain the size from there
|
5010 |
size = get_option_parameter(param, BLOCK_OPT_SIZE); |
5011 |
if (size && size->value.n == -1) { |
5012 |
if (backing_file && backing_file->value.s) {
|
5013 |
BlockDriverState *bs; |
5014 |
uint64_t size; |
5015 |
char buf[32]; |
5016 |
int back_flags;
|
5017 |
|
5018 |
/* backing files always opened read-only */
|
5019 |
back_flags = |
5020 |
flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
5021 |
|
5022 |
bs = bdrv_new("");
|
5023 |
|
5024 |
ret = bdrv_open(bs, backing_file->value.s, NULL, back_flags,
|
5025 |
backing_drv, &local_err); |
5026 |
if (ret < 0) { |
5027 |
error_setg_errno(errp, -ret, "Could not open '%s': %s",
|
5028 |
backing_file->value.s, |
5029 |
error_get_pretty(local_err)); |
5030 |
error_free(local_err); |
5031 |
local_err = NULL;
|
5032 |
bdrv_unref(bs); |
5033 |
goto out;
|
5034 |
} |
5035 |
bdrv_get_geometry(bs, &size); |
5036 |
size *= 512;
|
5037 |
|
5038 |
snprintf(buf, sizeof(buf), "%" PRId64, size); |
5039 |
set_option_parameter(param, BLOCK_OPT_SIZE, buf); |
5040 |
|
5041 |
bdrv_unref(bs); |
5042 |
} else {
|
5043 |
error_setg(errp, "Image creation needs a size parameter");
|
5044 |
goto out;
|
5045 |
} |
5046 |
} |
5047 |
|
5048 |
if (!quiet) {
|
5049 |
printf("Formatting '%s', fmt=%s ", filename, fmt);
|
5050 |
print_option_parameters(param); |
5051 |
puts("");
|
5052 |
} |
5053 |
ret = bdrv_create(drv, filename, param, &local_err); |
5054 |
if (ret == -EFBIG) {
|
5055 |
/* This is generally a better message than whatever the driver would
|
5056 |
* deliver (especially because of the cluster_size_hint), since that
|
5057 |
* is most probably not much different from "image too large". */
|
5058 |
const char *cluster_size_hint = ""; |
5059 |
if (get_option_parameter(create_options, BLOCK_OPT_CLUSTER_SIZE)) {
|
5060 |
cluster_size_hint = " (try using a larger cluster size)";
|
5061 |
} |
5062 |
error_setg(errp, "The image size is too large for file format '%s'"
|
5063 |
"%s", fmt, cluster_size_hint);
|
5064 |
error_free(local_err); |
5065 |
local_err = NULL;
|
5066 |
} |
5067 |
|
5068 |
out:
|
5069 |
free_option_parameters(create_options); |
5070 |
free_option_parameters(param); |
5071 |
|
5072 |
if (error_is_set(&local_err)) {
|
5073 |
error_propagate(errp, local_err); |
5074 |
} |
5075 |
} |
5076 |
|
5077 |
AioContext *bdrv_get_aio_context(BlockDriverState *bs) |
5078 |
{ |
5079 |
/* Currently BlockDriverState always uses the main loop AioContext */
|
5080 |
return qemu_get_aio_context();
|
5081 |
} |
5082 |
|
5083 |
void bdrv_add_before_write_notifier(BlockDriverState *bs,
|
5084 |
NotifierWithReturn *notifier) |
5085 |
{ |
5086 |
notifier_with_return_list_add(&bs->before_write_notifiers, notifier); |
5087 |
} |
5088 |
|
5089 |
int bdrv_amend_options(BlockDriverState *bs, QEMUOptionParameter *options)
|
5090 |
{ |
5091 |
if (bs->drv->bdrv_amend_options == NULL) { |
5092 |
return -ENOTSUP;
|
5093 |
} |
5094 |
return bs->drv->bdrv_amend_options(bs, options);
|
5095 |
} |
5096 |
|
5097 |
/* Used to recurse on single child block filters.
|
5098 |
* Single child block filter will store their child in bs->file.
|
5099 |
*/
|
5100 |
bool bdrv_generic_is_first_non_filter(BlockDriverState *bs,
|
5101 |
BlockDriverState *candidate) |
5102 |
{ |
5103 |
if (!bs->drv) {
|
5104 |
return false; |
5105 |
} |
5106 |
|
5107 |
if (!bs->drv->authorizations[BS_IS_A_FILTER]) {
|
5108 |
if (bs == candidate) {
|
5109 |
return true; |
5110 |
} else {
|
5111 |
return false; |
5112 |
} |
5113 |
} |
5114 |
|
5115 |
if (!bs->drv->authorizations[BS_FILTER_PASS_DOWN]) {
|
5116 |
return false; |
5117 |
} |
5118 |
|
5119 |
if (!bs->file) {
|
5120 |
return false; |
5121 |
} |
5122 |
|
5123 |
return bdrv_recurse_is_first_non_filter(bs->file, candidate);
|
5124 |
} |
5125 |
|
5126 |
bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
|
5127 |
BlockDriverState *candidate) |
5128 |
{ |
5129 |
if (bs->drv && bs->drv->bdrv_recurse_is_first_non_filter) {
|
5130 |
return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
|
5131 |
} |
5132 |
|
5133 |
return bdrv_generic_is_first_non_filter(bs, candidate);
|
5134 |
} |
5135 |
|
5136 |
/* This function checks if the candidate is the first non filter bs down it's
|
5137 |
* bs chain. Since we don't have pointers to parents it explore all bs chains
|
5138 |
* from the top. Some filters can choose not to pass down the recursion.
|
5139 |
*/
|
5140 |
bool bdrv_is_first_non_filter(BlockDriverState *candidate)
|
5141 |
{ |
5142 |
BlockDriverState *bs; |
5143 |
|
5144 |
/* walk down the bs forest recursively */
|
5145 |
QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
5146 |
bool perm;
|
5147 |
|
5148 |
if (!bs->file) {
|
5149 |
continue;
|
5150 |
} |
5151 |
|
5152 |
perm = bdrv_recurse_is_first_non_filter(bs->file, candidate); |
5153 |
|
5154 |
/* candidate is the first non filter */
|
5155 |
if (perm) {
|
5156 |
return true; |
5157 |
} |
5158 |
} |
5159 |
|
5160 |
return false; |
5161 |
} |