| /* |
| * QEMU System Emulator block driver |
| * |
| * Copyright (c) 2003 Fabrice Bellard |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| #include "config-host.h" |
| #include "qemu-common.h" |
| #include "trace.h" |
| #include "monitor.h" |
| #include "block_int.h" |
| #include "module.h" |
| #include "qjson.h" |
| #include "qemu-coroutine.h" |
| #include "qmp-commands.h" |
| #include "qemu-timer.h" |
| |
| #ifdef CONFIG_BSD |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/ioctl.h> |
| #include <sys/queue.h> |
| #ifndef __DragonFly__ |
| #include <sys/disk.h> |
| #endif |
| #endif |
| |
| #ifdef _WIN32 |
| #include <windows.h> |
| #endif |
| |
| #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ |
| |
| typedef enum { |
| BDRV_REQ_COPY_ON_READ = 0x1, |
| BDRV_REQ_ZERO_WRITE = 0x2, |
| } BdrvRequestFlags; |
| |
| static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); |
| static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque); |
| static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque); |
| static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov); |
| static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov); |
| static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, |
| BdrvRequestFlags flags); |
| static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, |
| BdrvRequestFlags flags); |
| static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, |
| int64_t sector_num, |
| QEMUIOVector *qiov, |
| int nb_sectors, |
| BlockDriverCompletionFunc *cb, |
| void *opaque, |
| bool is_write); |
| static void coroutine_fn bdrv_co_do_rw(void *opaque); |
| static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors); |
| |
| static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors, |
| bool is_write, double elapsed_time, uint64_t *wait); |
| static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write, |
| double elapsed_time, uint64_t *wait); |
| static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors, |
| bool is_write, int64_t *wait); |
| |
| static QTAILQ_HEAD(, BlockDriverState) bdrv_states = |
| QTAILQ_HEAD_INITIALIZER(bdrv_states); |
| |
| static QLIST_HEAD(, BlockDriver) bdrv_drivers = |
| QLIST_HEAD_INITIALIZER(bdrv_drivers); |
| |
| /* The device to use for VM snapshots */ |
| static BlockDriverState *bs_snapshots; |
| |
| /* If non-zero, use only whitelisted block drivers */ |
| static int use_bdrv_whitelist; |
| |
| #ifdef _WIN32 |
| static int is_windows_drive_prefix(const char *filename) |
| { |
| return (((filename[0] >= 'a' && filename[0] <= 'z') || |
| (filename[0] >= 'A' && filename[0] <= 'Z')) && |
| filename[1] == ':'); |
| } |
| |
| int is_windows_drive(const char *filename) |
| { |
| if (is_windows_drive_prefix(filename) && |
| filename[2] == '\0') |
| return 1; |
| if (strstart(filename, "\\\\.\\", NULL) || |
| strstart(filename, "//./", NULL)) |
| return 1; |
| return 0; |
| } |
| #endif |
| |
| /* throttling disk I/O limits */ |
| void bdrv_io_limits_disable(BlockDriverState *bs) |
| { |
| bs->io_limits_enabled = false; |
| |
| while (qemu_co_queue_next(&bs->throttled_reqs)); |
| |
| if (bs->block_timer) { |
| qemu_del_timer(bs->block_timer); |
| qemu_free_timer(bs->block_timer); |
| bs->block_timer = NULL; |
| } |
| |
| bs->slice_start = 0; |
| bs->slice_end = 0; |
| bs->slice_time = 0; |
| memset(&bs->io_base, 0, sizeof(bs->io_base)); |
| } |
| |
| static void bdrv_block_timer(void *opaque) |
| { |
| BlockDriverState *bs = opaque; |
| |
| qemu_co_queue_next(&bs->throttled_reqs); |
| } |
| |
| void bdrv_io_limits_enable(BlockDriverState *bs) |
| { |
| qemu_co_queue_init(&bs->throttled_reqs); |
| bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs); |
| bs->slice_time = 5 * BLOCK_IO_SLICE_TIME; |
| bs->slice_start = qemu_get_clock_ns(vm_clock); |
| bs->slice_end = bs->slice_start + bs->slice_time; |
| memset(&bs->io_base, 0, sizeof(bs->io_base)); |
| bs->io_limits_enabled = true; |
| } |
| |
| bool bdrv_io_limits_enabled(BlockDriverState *bs) |
| { |
| BlockIOLimit *io_limits = &bs->io_limits; |
| return io_limits->bps[BLOCK_IO_LIMIT_READ] |
| || io_limits->bps[BLOCK_IO_LIMIT_WRITE] |
| || io_limits->bps[BLOCK_IO_LIMIT_TOTAL] |
| || io_limits->iops[BLOCK_IO_LIMIT_READ] |
| || io_limits->iops[BLOCK_IO_LIMIT_WRITE] |
| || io_limits->iops[BLOCK_IO_LIMIT_TOTAL]; |
| } |
| |
| static void bdrv_io_limits_intercept(BlockDriverState *bs, |
| bool is_write, int nb_sectors) |
| { |
| int64_t wait_time = -1; |
| |
| if (!qemu_co_queue_empty(&bs->throttled_reqs)) { |
| qemu_co_queue_wait(&bs->throttled_reqs); |
| } |
| |
| /* In fact, we hope to keep each request's timing, in FIFO mode. The next |
| * throttled requests will not be dequeued until the current request is |
| * allowed to be serviced. So if the current request still exceeds the |
| * limits, it will be inserted to the head. All requests followed it will |
| * be still in throttled_reqs queue. |
| */ |
| |
| while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) { |
| qemu_mod_timer(bs->block_timer, |
| wait_time + qemu_get_clock_ns(vm_clock)); |
| qemu_co_queue_wait_insert_head(&bs->throttled_reqs); |
| } |
| |
| qemu_co_queue_next(&bs->throttled_reqs); |
| } |
| |
| /* check if the path starts with "<protocol>:" */ |
| static int path_has_protocol(const char *path) |
| { |
| const char *p; |
| |
| #ifdef _WIN32 |
| if (is_windows_drive(path) || |
| is_windows_drive_prefix(path)) { |
| return 0; |
| } |
| p = path + strcspn(path, ":/\\"); |
| #else |
| p = path + strcspn(path, ":/"); |
| #endif |
| |
| return *p == ':'; |
| } |
| |
| int path_is_absolute(const char *path) |
| { |
| #ifdef _WIN32 |
| /* specific case for names like: "\\.\d:" */ |
| if (is_windows_drive(path) || is_windows_drive_prefix(path)) { |
| return 1; |
| } |
| return (*path == '/' || *path == '\\'); |
| #else |
| return (*path == '/'); |
| #endif |
| } |
| |
| /* if filename is absolute, just copy it to dest. Otherwise, build a |
| path to it by considering it is relative to base_path. URL are |
| supported. */ |
| void path_combine(char *dest, int dest_size, |
| const char *base_path, |
| const char *filename) |
| { |
| const char *p, *p1; |
| int len; |
| |
| if (dest_size <= 0) |
| return; |
| if (path_is_absolute(filename)) { |
| pstrcpy(dest, dest_size, filename); |
| } else { |
| p = strchr(base_path, ':'); |
| if (p) |
| p++; |
| else |
| p = base_path; |
| p1 = strrchr(base_path, '/'); |
| #ifdef _WIN32 |
| { |
| const char *p2; |
| p2 = strrchr(base_path, '\\'); |
| if (!p1 || p2 > p1) |
| p1 = p2; |
| } |
| #endif |
| if (p1) |
| p1++; |
| else |
| p1 = base_path; |
| if (p1 > p) |
| p = p1; |
| len = p - base_path; |
| if (len > dest_size - 1) |
| len = dest_size - 1; |
| memcpy(dest, base_path, len); |
| dest[len] = '\0'; |
| pstrcat(dest, dest_size, filename); |
| } |
| } |
| |
| void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz) |
| { |
| if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) { |
| pstrcpy(dest, sz, bs->backing_file); |
| } else { |
| path_combine(dest, sz, bs->filename, bs->backing_file); |
| } |
| } |
| |
| void bdrv_register(BlockDriver *bdrv) |
| { |
| /* Block drivers without coroutine functions need emulation */ |
| if (!bdrv->bdrv_co_readv) { |
| bdrv->bdrv_co_readv = bdrv_co_readv_em; |
| bdrv->bdrv_co_writev = bdrv_co_writev_em; |
| |
| /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if |
| * the block driver lacks aio we need to emulate that too. |
| */ |
| if (!bdrv->bdrv_aio_readv) { |
| /* add AIO emulation layer */ |
| bdrv->bdrv_aio_readv = bdrv_aio_readv_em; |
| bdrv->bdrv_aio_writev = bdrv_aio_writev_em; |
| } |
| } |
| |
| QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); |
| } |
| |
| /* create a new block device (by default it is empty) */ |
| BlockDriverState *bdrv_new(const char *device_name) |
| { |
| BlockDriverState *bs; |
| |
| bs = g_malloc0(sizeof(BlockDriverState)); |
| pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); |
| if (device_name[0] != '\0') { |
| QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); |
| } |
| bdrv_iostatus_disable(bs); |
| return bs; |
| } |
| |
| BlockDriver *bdrv_find_format(const char *format_name) |
| { |
| BlockDriver *drv1; |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (!strcmp(drv1->format_name, format_name)) { |
| return drv1; |
| } |
| } |
| return NULL; |
| } |
| |
| static int bdrv_is_whitelisted(BlockDriver *drv) |
| { |
| static const char *whitelist[] = { |
| CONFIG_BDRV_WHITELIST |
| }; |
| const char **p; |
| |
| if (!whitelist[0]) |
| return 1; /* no whitelist, anything goes */ |
| |
| for (p = whitelist; *p; p++) { |
| if (!strcmp(drv->format_name, *p)) { |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| BlockDriver *bdrv_find_whitelisted_format(const char *format_name) |
| { |
| BlockDriver *drv = bdrv_find_format(format_name); |
| return drv && bdrv_is_whitelisted(drv) ? drv : NULL; |
| } |
| |
| typedef struct CreateCo { |
| BlockDriver *drv; |
| char *filename; |
| QEMUOptionParameter *options; |
| int ret; |
| } CreateCo; |
| |
| static void coroutine_fn bdrv_create_co_entry(void *opaque) |
| { |
| CreateCo *cco = opaque; |
| assert(cco->drv); |
| |
| cco->ret = cco->drv->bdrv_create(cco->filename, cco->options); |
| } |
| |
| int bdrv_create(BlockDriver *drv, const char* filename, |
| QEMUOptionParameter *options) |
| { |
| int ret; |
| |
| Coroutine *co; |
| CreateCo cco = { |
| .drv = drv, |
| .filename = g_strdup(filename), |
| .options = options, |
| .ret = NOT_DONE, |
| }; |
| |
| if (!drv->bdrv_create) { |
| return -ENOTSUP; |
| } |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_create_co_entry(&cco); |
| } else { |
| co = qemu_coroutine_create(bdrv_create_co_entry); |
| qemu_coroutine_enter(co, &cco); |
| while (cco.ret == NOT_DONE) { |
| qemu_aio_wait(); |
| } |
| } |
| |
| ret = cco.ret; |
| g_free(cco.filename); |
| |
| return ret; |
| } |
| |
| int bdrv_create_file(const char* filename, QEMUOptionParameter *options) |
| { |
| BlockDriver *drv; |
| |
| drv = bdrv_find_protocol(filename); |
| if (drv == NULL) { |
| return -ENOENT; |
| } |
| |
| return bdrv_create(drv, filename, options); |
| } |
| |
| /* |
| * Create a uniquely-named empty temporary file. |
| * Return 0 upon success, otherwise a negative errno value. |
| */ |
| int get_tmp_filename(char *filename, int size) |
| { |
| #ifdef _WIN32 |
| char temp_dir[MAX_PATH]; |
| /* GetTempFileName requires that its output buffer (4th param) |
| have length MAX_PATH or greater. */ |
| assert(size >= MAX_PATH); |
| return (GetTempPath(MAX_PATH, temp_dir) |
| && GetTempFileName(temp_dir, "qem", 0, filename) |
| ? 0 : -GetLastError()); |
| #else |
| int fd; |
| const char *tmpdir; |
| tmpdir = getenv("TMPDIR"); |
| if (!tmpdir) |
| tmpdir = "/tmp"; |
| if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { |
| return -EOVERFLOW; |
| } |
| fd = mkstemp(filename); |
| if (fd < 0 || close(fd)) { |
| return -errno; |
| } |
| return 0; |
| #endif |
| } |
| |
| /* |
| * Detect host devices. By convention, /dev/cdrom[N] is always |
| * recognized as a host CDROM. |
| */ |
| static BlockDriver *find_hdev_driver(const char *filename) |
| { |
| int score_max = 0, score; |
| BlockDriver *drv = NULL, *d; |
| |
| QLIST_FOREACH(d, &bdrv_drivers, list) { |
| if (d->bdrv_probe_device) { |
| score = d->bdrv_probe_device(filename); |
| if (score > score_max) { |
| score_max = score; |
| drv = d; |
| } |
| } |
| } |
| |
| return drv; |
| } |
| |
| BlockDriver *bdrv_find_protocol(const char *filename) |
| { |
| BlockDriver *drv1; |
| char protocol[128]; |
| int len; |
| const char *p; |
| |
| /* TODO Drivers without bdrv_file_open must be specified explicitly */ |
| |
| /* |
| * XXX(hch): we really should not let host device detection |
| * override an explicit protocol specification, but moving this |
| * later breaks access to device names with colons in them. |
| * Thanks to the brain-dead persistent naming schemes on udev- |
| * based Linux systems those actually are quite common. |
| */ |
| drv1 = find_hdev_driver(filename); |
| if (drv1) { |
| return drv1; |
| } |
| |
| if (!path_has_protocol(filename)) { |
| return bdrv_find_format("file"); |
| } |
| p = strchr(filename, ':'); |
| assert(p != NULL); |
| len = p - filename; |
| if (len > sizeof(protocol) - 1) |
| len = sizeof(protocol) - 1; |
| memcpy(protocol, filename, len); |
| protocol[len] = '\0'; |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (drv1->protocol_name && |
| !strcmp(drv1->protocol_name, protocol)) { |
| return drv1; |
| } |
| } |
| return NULL; |
| } |
| |
| static int find_image_format(const char *filename, BlockDriver **pdrv) |
| { |
| int ret, score, score_max; |
| BlockDriver *drv1, *drv; |
| uint8_t buf[2048]; |
| BlockDriverState *bs; |
| |
| ret = bdrv_file_open(&bs, filename, 0); |
| if (ret < 0) { |
| *pdrv = NULL; |
| return ret; |
| } |
| |
| /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ |
| if (bs->sg || !bdrv_is_inserted(bs)) { |
| bdrv_delete(bs); |
| drv = bdrv_find_format("raw"); |
| if (!drv) { |
| ret = -ENOENT; |
| } |
| *pdrv = drv; |
| return ret; |
| } |
| |
| ret = bdrv_pread(bs, 0, buf, sizeof(buf)); |
| bdrv_delete(bs); |
| if (ret < 0) { |
| *pdrv = NULL; |
| return ret; |
| } |
| |
| score_max = 0; |
| drv = NULL; |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (drv1->bdrv_probe) { |
| score = drv1->bdrv_probe(buf, ret, filename); |
| if (score > score_max) { |
| score_max = score; |
| drv = drv1; |
| } |
| } |
| } |
| if (!drv) { |
| ret = -ENOENT; |
| } |
| *pdrv = drv; |
| return ret; |
| } |
| |
| /** |
| * Set the current 'total_sectors' value |
| */ |
| static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ |
| if (bs->sg) |
| return 0; |
| |
| /* query actual device if possible, otherwise just trust the hint */ |
| if (drv->bdrv_getlength) { |
| int64_t length = drv->bdrv_getlength(bs); |
| if (length < 0) { |
| return length; |
| } |
| hint = length >> BDRV_SECTOR_BITS; |
| } |
| |
| bs->total_sectors = hint; |
| return 0; |
| } |
| |
| /** |
| * Set open flags for a given cache mode |
| * |
| * Return 0 on success, -1 if the cache mode was invalid. |
| */ |
| int bdrv_parse_cache_flags(const char *mode, int *flags) |
| { |
| *flags &= ~BDRV_O_CACHE_MASK; |
| |
| if (!strcmp(mode, "off") || !strcmp(mode, "none")) { |
| *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; |
| } else if (!strcmp(mode, "directsync")) { |
| *flags |= BDRV_O_NOCACHE; |
| } else if (!strcmp(mode, "writeback")) { |
| *flags |= BDRV_O_CACHE_WB; |
| } else if (!strcmp(mode, "unsafe")) { |
| *flags |= BDRV_O_CACHE_WB; |
| *flags |= BDRV_O_NO_FLUSH; |
| } else if (!strcmp(mode, "writethrough")) { |
| /* this is the default */ |
| } else { |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * The copy-on-read flag is actually a reference count so multiple users may |
| * use the feature without worrying about clobbering its previous state. |
| * Copy-on-read stays enabled until all users have called to disable it. |
| */ |
| void bdrv_enable_copy_on_read(BlockDriverState *bs) |
| { |
| bs->copy_on_read++; |
| } |
| |
| void bdrv_disable_copy_on_read(BlockDriverState *bs) |
| { |
| assert(bs->copy_on_read > 0); |
| bs->copy_on_read--; |
| } |
| |
| /* |
| * Common part for opening disk images and files |
| */ |
| static int bdrv_open_common(BlockDriverState *bs, const char *filename, |
| int flags, BlockDriver *drv) |
| { |
| int ret, open_flags; |
| |
| assert(drv != NULL); |
| assert(bs->file == NULL); |
| |
| trace_bdrv_open_common(bs, filename, flags, drv->format_name); |
| |
| bs->open_flags = flags; |
| bs->buffer_alignment = 512; |
| |
| assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ |
| if ((flags & BDRV_O_RDWR) && (flags & BDRV_O_COPY_ON_READ)) { |
| bdrv_enable_copy_on_read(bs); |
| } |
| |
| pstrcpy(bs->filename, sizeof(bs->filename), filename); |
| |
| if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) { |
| return -ENOTSUP; |
| } |
| |
| bs->drv = drv; |
| bs->opaque = g_malloc0(drv->instance_size); |
| |
| bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); |
| open_flags = flags | BDRV_O_CACHE_WB; |
| |
| /* |
| * Clear flags that are internal to the block layer before opening the |
| * image. |
| */ |
| open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
| |
| /* |
| * Snapshots should be writable. |
| */ |
| if (bs->is_temporary) { |
| open_flags |= BDRV_O_RDWR; |
| } |
| |
| bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR); |
| |
| /* Open the image, either directly or using a protocol */ |
| if (drv->bdrv_file_open) { |
| ret = drv->bdrv_file_open(bs, filename, open_flags); |
| } else { |
| ret = bdrv_file_open(&bs->file, filename, open_flags); |
| if (ret >= 0) { |
| ret = drv->bdrv_open(bs, open_flags); |
| } |
| } |
| |
| if (ret < 0) { |
| goto free_and_fail; |
| } |
| |
| ret = refresh_total_sectors(bs, bs->total_sectors); |
| if (ret < 0) { |
| goto free_and_fail; |
| } |
| |
| #ifndef _WIN32 |
| if (bs->is_temporary) { |
| unlink(filename); |
| } |
| #endif |
| return 0; |
| |
| free_and_fail: |
| if (bs->file) { |
| bdrv_delete(bs->file); |
| bs->file = NULL; |
| } |
| g_free(bs->opaque); |
| bs->opaque = NULL; |
| bs->drv = NULL; |
| return ret; |
| } |
| |
| /* |
| * Opens a file using a protocol (file, host_device, nbd, ...) |
| */ |
| int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags) |
| { |
| BlockDriverState *bs; |
| BlockDriver *drv; |
| int ret; |
| |
| drv = bdrv_find_protocol(filename); |
| if (!drv) { |
| return -ENOENT; |
| } |
| |
| bs = bdrv_new(""); |
| ret = bdrv_open_common(bs, filename, flags, drv); |
| if (ret < 0) { |
| bdrv_delete(bs); |
| return ret; |
| } |
| bs->growable = 1; |
| *pbs = bs; |
| return 0; |
| } |
| |
| /* |
| * Opens a disk image (raw, qcow2, vmdk, ...) |
| */ |
| int bdrv_open(BlockDriverState *bs, const char *filename, int flags, |
| BlockDriver *drv) |
| { |
| int ret; |
| char tmp_filename[PATH_MAX]; |
| |
| if (flags & BDRV_O_SNAPSHOT) { |
| BlockDriverState *bs1; |
| int64_t total_size; |
| int is_protocol = 0; |
| BlockDriver *bdrv_qcow2; |
| QEMUOptionParameter *options; |
| char backing_filename[PATH_MAX]; |
| |
| /* if snapshot, we create a temporary backing file and open it |
| instead of opening 'filename' directly */ |
| |
| /* if there is a backing file, use it */ |
| bs1 = bdrv_new(""); |
| ret = bdrv_open(bs1, filename, 0, drv); |
| if (ret < 0) { |
| bdrv_delete(bs1); |
| return ret; |
| } |
| total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK; |
| |
| if (bs1->drv && bs1->drv->protocol_name) |
| is_protocol = 1; |
| |
| bdrv_delete(bs1); |
| |
| ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename)); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* Real path is meaningless for protocols */ |
| if (is_protocol) |
| snprintf(backing_filename, sizeof(backing_filename), |
| "%s", filename); |
| else if (!realpath(filename, backing_filename)) |
| return -errno; |
| |
| bdrv_qcow2 = bdrv_find_format("qcow2"); |
| options = parse_option_parameters("", bdrv_qcow2->create_options, NULL); |
| |
| set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size); |
| set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename); |
| if (drv) { |
| set_option_parameter(options, BLOCK_OPT_BACKING_FMT, |
| drv->format_name); |
| } |
| |
| ret = bdrv_create(bdrv_qcow2, tmp_filename, options); |
| free_option_parameters(options); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| filename = tmp_filename; |
| drv = bdrv_qcow2; |
| bs->is_temporary = 1; |
| } |
| |
| /* Find the right image format driver */ |
| if (!drv) { |
| ret = find_image_format(filename, &drv); |
| } |
| |
| if (!drv) { |
| goto unlink_and_fail; |
| } |
| |
| /* Open the image */ |
| ret = bdrv_open_common(bs, filename, flags, drv); |
| if (ret < 0) { |
| goto unlink_and_fail; |
| } |
| |
| /* If there is a backing file, use it */ |
| if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') { |
| char backing_filename[PATH_MAX]; |
| int back_flags; |
| BlockDriver *back_drv = NULL; |
| |
| bs->backing_hd = bdrv_new(""); |
| bdrv_get_full_backing_filename(bs, backing_filename, |
| sizeof(backing_filename)); |
| |
| if (bs->backing_format[0] != '\0') { |
| back_drv = bdrv_find_format(bs->backing_format); |
| } |
| |
| /* backing files always opened read-only */ |
| back_flags = |
| flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
| |
| ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv); |
| if (ret < 0) { |
| bdrv_close(bs); |
| return ret; |
| } |
| if (bs->is_temporary) { |
| bs->backing_hd->keep_read_only = !(flags & BDRV_O_RDWR); |
| } else { |
| /* base image inherits from "parent" */ |
| bs->backing_hd->keep_read_only = bs->keep_read_only; |
| } |
| } |
| |
| if (!bdrv_key_required(bs)) { |
| bdrv_dev_change_media_cb(bs, true); |
| } |
| |
| /* throttling disk I/O limits */ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_enable(bs); |
| } |
| |
| return 0; |
| |
| unlink_and_fail: |
| if (bs->is_temporary) { |
| unlink(filename); |
| } |
| return ret; |
| } |
| |
| void bdrv_close(BlockDriverState *bs) |
| { |
| bdrv_flush(bs); |
| if (bs->drv) { |
| if (bs->job) { |
| block_job_cancel_sync(bs->job); |
| } |
| bdrv_drain_all(); |
| |
| if (bs == bs_snapshots) { |
| bs_snapshots = NULL; |
| } |
| if (bs->backing_hd) { |
| bdrv_delete(bs->backing_hd); |
| bs->backing_hd = NULL; |
| } |
| bs->drv->bdrv_close(bs); |
| g_free(bs->opaque); |
| #ifdef _WIN32 |
| if (bs->is_temporary) { |
| unlink(bs->filename); |
| } |
| #endif |
| bs->opaque = NULL; |
| bs->drv = NULL; |
| bs->copy_on_read = 0; |
| bs->backing_file[0] = '\0'; |
| bs->backing_format[0] = '\0'; |
| bs->total_sectors = 0; |
| bs->encrypted = 0; |
| bs->valid_key = 0; |
| bs->sg = 0; |
| bs->growable = 0; |
| |
| if (bs->file != NULL) { |
| bdrv_delete(bs->file); |
| bs->file = NULL; |
| } |
| |
| bdrv_dev_change_media_cb(bs, false); |
| } |
| |
| /*throttling disk I/O limits*/ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_disable(bs); |
| } |
| } |
| |
| void bdrv_close_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| bdrv_close(bs); |
| } |
| } |
| |
| /* |
| * Wait for pending requests to complete across all BlockDriverStates |
| * |
| * This function does not flush data to disk, use bdrv_flush_all() for that |
| * after calling this function. |
| * |
| * Note that completion of an asynchronous I/O operation can trigger any |
| * number of other I/O operations on other devices---for example a coroutine |
| * can be arbitrarily complex and a constant flow of I/O can come until the |
| * coroutine is complete. Because of this, it is not possible to have a |
| * function to drain a single device's I/O queue. |
| */ |
| void bdrv_drain_all(void) |
| { |
| BlockDriverState *bs; |
| bool busy; |
| |
| do { |
| busy = qemu_aio_wait(); |
| |
| /* FIXME: We do not have timer support here, so this is effectively |
| * a busy wait. |
| */ |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| if (!qemu_co_queue_empty(&bs->throttled_reqs)) { |
| qemu_co_queue_restart_all(&bs->throttled_reqs); |
| busy = true; |
| } |
| } |
| } while (busy); |
| |
| /* If requests are still pending there is a bug somewhere */ |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| assert(QLIST_EMPTY(&bs->tracked_requests)); |
| assert(qemu_co_queue_empty(&bs->throttled_reqs)); |
| } |
| } |
| |
| /* make a BlockDriverState anonymous by removing from bdrv_state list. |
| Also, NULL terminate the device_name to prevent double remove */ |
| void bdrv_make_anon(BlockDriverState *bs) |
| { |
| if (bs->device_name[0] != '\0') { |
| QTAILQ_REMOVE(&bdrv_states, bs, list); |
| } |
| bs->device_name[0] = '\0'; |
| } |
| |
| static void bdrv_rebind(BlockDriverState *bs) |
| { |
| if (bs->drv && bs->drv->bdrv_rebind) { |
| bs->drv->bdrv_rebind(bs); |
| } |
| } |
| |
| static void bdrv_move_feature_fields(BlockDriverState *bs_dest, |
| BlockDriverState *bs_src) |
| { |
| /* move some fields that need to stay attached to the device */ |
| bs_dest->open_flags = bs_src->open_flags; |
| |
| /* dev info */ |
| bs_dest->dev_ops = bs_src->dev_ops; |
| bs_dest->dev_opaque = bs_src->dev_opaque; |
| bs_dest->dev = bs_src->dev; |
| bs_dest->buffer_alignment = bs_src->buffer_alignment; |
| bs_dest->copy_on_read = bs_src->copy_on_read; |
| |
| bs_dest->enable_write_cache = bs_src->enable_write_cache; |
| |
| /* i/o timing parameters */ |
| bs_dest->slice_time = bs_src->slice_time; |
| bs_dest->slice_start = bs_src->slice_start; |
| bs_dest->slice_end = bs_src->slice_end; |
| bs_dest->io_limits = bs_src->io_limits; |
| bs_dest->io_base = bs_src->io_base; |
| bs_dest->throttled_reqs = bs_src->throttled_reqs; |
| bs_dest->block_timer = bs_src->block_timer; |
| bs_dest->io_limits_enabled = bs_src->io_limits_enabled; |
| |
| /* r/w error */ |
| bs_dest->on_read_error = bs_src->on_read_error; |
| bs_dest->on_write_error = bs_src->on_write_error; |
| |
| /* i/o status */ |
| bs_dest->iostatus_enabled = bs_src->iostatus_enabled; |
| bs_dest->iostatus = bs_src->iostatus; |
| |
| /* dirty bitmap */ |
| bs_dest->dirty_count = bs_src->dirty_count; |
| bs_dest->dirty_bitmap = bs_src->dirty_bitmap; |
| |
| /* job */ |
| bs_dest->in_use = bs_src->in_use; |
| bs_dest->job = bs_src->job; |
| |
| /* keep the same entry in bdrv_states */ |
| pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name), |
| bs_src->device_name); |
| bs_dest->list = bs_src->list; |
| } |
| |
| /* |
| * Swap bs contents for two image chains while they are live, |
| * while keeping required fields on the BlockDriverState that is |
| * actually attached to a device. |
| * |
| * This will modify the BlockDriverState fields, and swap contents |
| * between bs_new and bs_old. Both bs_new and bs_old are modified. |
| * |
| * bs_new is required to be anonymous. |
| * |
| * This function does not create any image files. |
| */ |
| void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) |
| { |
| BlockDriverState tmp; |
| |
| /* bs_new must be anonymous and shouldn't have anything fancy enabled */ |
| assert(bs_new->device_name[0] == '\0'); |
| assert(bs_new->dirty_bitmap == NULL); |
| assert(bs_new->job == NULL); |
| assert(bs_new->dev == NULL); |
| assert(bs_new->in_use == 0); |
| assert(bs_new->io_limits_enabled == false); |
| assert(bs_new->block_timer == NULL); |
| |
| tmp = *bs_new; |
| *bs_new = *bs_old; |
| *bs_old = tmp; |
| |
| /* there are some fields that should not be swapped, move them back */ |
| bdrv_move_feature_fields(&tmp, bs_old); |
| bdrv_move_feature_fields(bs_old, bs_new); |
| bdrv_move_feature_fields(bs_new, &tmp); |
| |
| /* bs_new shouldn't be in bdrv_states even after the swap! */ |
| assert(bs_new->device_name[0] == '\0'); |
| |
| /* Check a few fields that should remain attached to the device */ |
| assert(bs_new->dev == NULL); |
| assert(bs_new->job == NULL); |
| assert(bs_new->in_use == 0); |
| assert(bs_new->io_limits_enabled == false); |
| assert(bs_new->block_timer == NULL); |
| |
| bdrv_rebind(bs_new); |
| bdrv_rebind(bs_old); |
| } |
| |
| /* |
| * Add new bs contents at the top of an image chain while the chain is |
| * live, while keeping required fields on the top layer. |
| * |
| * This will modify the BlockDriverState fields, and swap contents |
| * between bs_new and bs_top. Both bs_new and bs_top are modified. |
| * |
| * bs_new is required to be anonymous. |
| * |
| * This function does not create any image files. |
| */ |
| void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) |
| { |
| bdrv_swap(bs_new, bs_top); |
| |
| /* The contents of 'tmp' will become bs_top, as we are |
| * swapping bs_new and bs_top contents. */ |
| bs_top->backing_hd = bs_new; |
| bs_top->open_flags &= ~BDRV_O_NO_BACKING; |
| pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file), |
| bs_new->filename); |
| pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format), |
| bs_new->drv ? bs_new->drv->format_name : ""); |
| } |
| |
| void bdrv_delete(BlockDriverState *bs) |
| { |
| assert(!bs->dev); |
| assert(!bs->job); |
| assert(!bs->in_use); |
| |
| /* remove from list, if necessary */ |
| bdrv_make_anon(bs); |
| |
| bdrv_close(bs); |
| |
| assert(bs != bs_snapshots); |
| g_free(bs); |
| } |
| |
| int bdrv_attach_dev(BlockDriverState *bs, void *dev) |
| /* TODO change to DeviceState *dev when all users are qdevified */ |
| { |
| if (bs->dev) { |
| return -EBUSY; |
| } |
| bs->dev = dev; |
| bdrv_iostatus_reset(bs); |
| return 0; |
| } |
| |
| /* TODO qdevified devices don't use this, remove when devices are qdevified */ |
| void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev) |
| { |
| if (bdrv_attach_dev(bs, dev) < 0) { |
| abort(); |
| } |
| } |
| |
| void bdrv_detach_dev(BlockDriverState *bs, void *dev) |
| /* TODO change to DeviceState *dev when all users are qdevified */ |
| { |
| assert(bs->dev == dev); |
| bs->dev = NULL; |
| bs->dev_ops = NULL; |
| bs->dev_opaque = NULL; |
| bs->buffer_alignment = 512; |
| } |
| |
| /* TODO change to return DeviceState * when all users are qdevified */ |
| void *bdrv_get_attached_dev(BlockDriverState *bs) |
| { |
| return bs->dev; |
| } |
| |
| void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, |
| void *opaque) |
| { |
| bs->dev_ops = ops; |
| bs->dev_opaque = opaque; |
| if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) { |
| bs_snapshots = NULL; |
| } |
| } |
| |
| void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, |
| BlockQMPEventAction action, int is_read) |
| { |
| QObject *data; |
| const char *action_str; |
| |
| switch (action) { |
| case BDRV_ACTION_REPORT: |
| action_str = "report"; |
| break; |
| case BDRV_ACTION_IGNORE: |
| action_str = "ignore"; |
| break; |
| case BDRV_ACTION_STOP: |
| action_str = "stop"; |
| break; |
| default: |
| abort(); |
| } |
| |
| data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }", |
| bdrv->device_name, |
| action_str, |
| is_read ? "read" : "write"); |
| monitor_protocol_event(QEVENT_BLOCK_IO_ERROR, data); |
| |
| qobject_decref(data); |
| } |
| |
| static void bdrv_emit_qmp_eject_event(BlockDriverState *bs, bool ejected) |
| { |
| QObject *data; |
| |
| data = qobject_from_jsonf("{ 'device': %s, 'tray-open': %i }", |
| bdrv_get_device_name(bs), ejected); |
| monitor_protocol_event(QEVENT_DEVICE_TRAY_MOVED, data); |
| |
| qobject_decref(data); |
| } |
| |
| static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load) |
| { |
| if (bs->dev_ops && bs->dev_ops->change_media_cb) { |
| bool tray_was_closed = !bdrv_dev_is_tray_open(bs); |
| bs->dev_ops->change_media_cb(bs->dev_opaque, load); |
| if (tray_was_closed) { |
| /* tray open */ |
| bdrv_emit_qmp_eject_event(bs, true); |
| } |
| if (load) { |
| /* tray close */ |
| bdrv_emit_qmp_eject_event(bs, false); |
| } |
| } |
| } |
| |
| bool bdrv_dev_has_removable_media(BlockDriverState *bs) |
| { |
| return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb); |
| } |
| |
| void bdrv_dev_eject_request(BlockDriverState *bs, bool force) |
| { |
| if (bs->dev_ops && bs->dev_ops->eject_request_cb) { |
| bs->dev_ops->eject_request_cb(bs->dev_opaque, force); |
| } |
| } |
| |
| bool bdrv_dev_is_tray_open(BlockDriverState *bs) |
| { |
| if (bs->dev_ops && bs->dev_ops->is_tray_open) { |
| return bs->dev_ops->is_tray_open(bs->dev_opaque); |
| } |
| return false; |
| } |
| |
| static void bdrv_dev_resize_cb(BlockDriverState *bs) |
| { |
| if (bs->dev_ops && bs->dev_ops->resize_cb) { |
| bs->dev_ops->resize_cb(bs->dev_opaque); |
| } |
| } |
| |
| bool bdrv_dev_is_medium_locked(BlockDriverState *bs) |
| { |
| if (bs->dev_ops && bs->dev_ops->is_medium_locked) { |
| return bs->dev_ops->is_medium_locked(bs->dev_opaque); |
| } |
| return false; |
| } |
| |
| /* |
| * Run consistency checks on an image |
| * |
| * Returns 0 if the check could be completed (it doesn't mean that the image is |
| * free of errors) or -errno when an internal error occurred. The results of the |
| * check are stored in res. |
| */ |
| int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) |
| { |
| if (bs->drv->bdrv_check == NULL) { |
| return -ENOTSUP; |
| } |
| |
| memset(res, 0, sizeof(*res)); |
| return bs->drv->bdrv_check(bs, res, fix); |
| } |
| |
| #define COMMIT_BUF_SECTORS 2048 |
| |
| /* commit COW file into the raw image */ |
| int bdrv_commit(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| BlockDriver *backing_drv; |
| int64_t sector, total_sectors; |
| int n, ro, open_flags; |
| int ret = 0, rw_ret = 0; |
| uint8_t *buf; |
| char filename[1024]; |
| BlockDriverState *bs_rw, *bs_ro; |
| |
| if (!drv) |
| return -ENOMEDIUM; |
| |
| if (!bs->backing_hd) { |
| return -ENOTSUP; |
| } |
| |
| if (bs->backing_hd->keep_read_only) { |
| return -EACCES; |
| } |
| |
| if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) { |
| return -EBUSY; |
| } |
| |
| backing_drv = bs->backing_hd->drv; |
| ro = bs->backing_hd->read_only; |
| strncpy(filename, bs->backing_hd->filename, sizeof(filename)); |
| open_flags = bs->backing_hd->open_flags; |
| |
| if (ro) { |
| /* re-open as RW */ |
| bdrv_delete(bs->backing_hd); |
| bs->backing_hd = NULL; |
| bs_rw = bdrv_new(""); |
| rw_ret = bdrv_open(bs_rw, filename, open_flags | BDRV_O_RDWR, |
| backing_drv); |
| if (rw_ret < 0) { |
| bdrv_delete(bs_rw); |
| /* try to re-open read-only */ |
| bs_ro = bdrv_new(""); |
| ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, |
| backing_drv); |
| if (ret < 0) { |
| bdrv_delete(bs_ro); |
| /* drive not functional anymore */ |
| bs->drv = NULL; |
| return ret; |
| } |
| bs->backing_hd = bs_ro; |
| return rw_ret; |
| } |
| bs->backing_hd = bs_rw; |
| } |
| |
| total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; |
| buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); |
| |
| for (sector = 0; sector < total_sectors; sector += n) { |
| if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) { |
| |
| if (bdrv_read(bs, sector, buf, n) != 0) { |
| ret = -EIO; |
| goto ro_cleanup; |
| } |
| |
| if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) { |
| ret = -EIO; |
| goto ro_cleanup; |
| } |
| } |
| } |
| |
| if (drv->bdrv_make_empty) { |
| ret = drv->bdrv_make_empty(bs); |
| bdrv_flush(bs); |
| } |
| |
| /* |
| * Make sure all data we wrote to the backing device is actually |
| * stable on disk. |
| */ |
| if (bs->backing_hd) |
| bdrv_flush(bs->backing_hd); |
| |
| ro_cleanup: |
| g_free(buf); |
| |
| if (ro) { |
| /* re-open as RO */ |
| bdrv_delete(bs->backing_hd); |
| bs->backing_hd = NULL; |
| bs_ro = bdrv_new(""); |
| ret = bdrv_open(bs_ro, filename, open_flags & ~BDRV_O_RDWR, |
| backing_drv); |
| if (ret < 0) { |
| bdrv_delete(bs_ro); |
| /* drive not functional anymore */ |
| bs->drv = NULL; |
| return ret; |
| } |
| bs->backing_hd = bs_ro; |
| bs->backing_hd->keep_read_only = 0; |
| } |
| |
| return ret; |
| } |
| |
| int bdrv_commit_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| int ret = bdrv_commit(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| return 0; |
| } |
| |
| struct BdrvTrackedRequest { |
| BlockDriverState *bs; |
| int64_t sector_num; |
| int nb_sectors; |
| bool is_write; |
| QLIST_ENTRY(BdrvTrackedRequest) list; |
| Coroutine *co; /* owner, used for deadlock detection */ |
| CoQueue wait_queue; /* coroutines blocked on this request */ |
| }; |
| |
| /** |
| * Remove an active request from the tracked requests list |
| * |
| * This function should be called when a tracked request is completing. |
| */ |
| static void tracked_request_end(BdrvTrackedRequest *req) |
| { |
| QLIST_REMOVE(req, list); |
| qemu_co_queue_restart_all(&req->wait_queue); |
| } |
| |
| /** |
| * Add an active request to the tracked requests list |
| */ |
| static void tracked_request_begin(BdrvTrackedRequest *req, |
| BlockDriverState *bs, |
| int64_t sector_num, |
| int nb_sectors, bool is_write) |
| { |
| *req = (BdrvTrackedRequest){ |
| .bs = bs, |
| .sector_num = sector_num, |
| .nb_sectors = nb_sectors, |
| .is_write = is_write, |
| .co = qemu_coroutine_self(), |
| }; |
| |
| qemu_co_queue_init(&req->wait_queue); |
| |
| QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); |
| } |
| |
| /** |
| * Round a region to cluster boundaries |
| */ |
| static void round_to_clusters(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| int64_t *cluster_sector_num, |
| int *cluster_nb_sectors) |
| { |
| BlockDriverInfo bdi; |
| |
| if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { |
| *cluster_sector_num = sector_num; |
| *cluster_nb_sectors = nb_sectors; |
| } else { |
| int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; |
| *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); |
| *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + |
| nb_sectors, c); |
| } |
| } |
| |
| static bool tracked_request_overlaps(BdrvTrackedRequest *req, |
| int64_t sector_num, int nb_sectors) { |
| /* aaaa bbbb */ |
| if (sector_num >= req->sector_num + req->nb_sectors) { |
| return false; |
| } |
| /* bbbb aaaa */ |
| if (req->sector_num >= sector_num + nb_sectors) { |
| return false; |
| } |
| return true; |
| } |
| |
| static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors) |
| { |
| BdrvTrackedRequest *req; |
| int64_t cluster_sector_num; |
| int cluster_nb_sectors; |
| bool retry; |
| |
| /* If we touch the same cluster it counts as an overlap. This guarantees |
| * that allocating writes will be serialized and not race with each other |
| * for the same cluster. For example, in copy-on-read it ensures that the |
| * CoR read and write operations are atomic and guest writes cannot |
| * interleave between them. |
| */ |
| round_to_clusters(bs, sector_num, nb_sectors, |
| &cluster_sector_num, &cluster_nb_sectors); |
| |
| do { |
| retry = false; |
| QLIST_FOREACH(req, &bs->tracked_requests, list) { |
| if (tracked_request_overlaps(req, cluster_sector_num, |
| cluster_nb_sectors)) { |
| /* Hitting this means there was a reentrant request, for |
| * example, a block driver issuing nested requests. This must |
| * never happen since it means deadlock. |
| */ |
| assert(qemu_coroutine_self() != req->co); |
| |
| qemu_co_queue_wait(&req->wait_queue); |
| retry = true; |
| break; |
| } |
| } |
| } while (retry); |
| } |
| |
| /* |
| * Return values: |
| * 0 - success |
| * -EINVAL - backing format specified, but no file |
| * -ENOSPC - can't update the backing file because no space is left in the |
| * image file header |
| * -ENOTSUP - format driver doesn't support changing the backing file |
| */ |
| int bdrv_change_backing_file(BlockDriverState *bs, |
| const char *backing_file, const char *backing_fmt) |
| { |
| BlockDriver *drv = bs->drv; |
| int ret; |
| |
| /* Backing file format doesn't make sense without a backing file */ |
| if (backing_fmt && !backing_file) { |
| return -EINVAL; |
| } |
| |
| if (drv->bdrv_change_backing_file != NULL) { |
| ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); |
| } else { |
| ret = -ENOTSUP; |
| } |
| |
| if (ret == 0) { |
| pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
| pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
| } |
| return ret; |
| } |
| |
| static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, |
| size_t size) |
| { |
| int64_t len; |
| |
| if (!bdrv_is_inserted(bs)) |
| return -ENOMEDIUM; |
| |
| if (bs->growable) |
| return 0; |
| |
| len = bdrv_getlength(bs); |
| |
| if (offset < 0) |
| return -EIO; |
| |
| if ((offset > len) || (len - offset < size)) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors) |
| { |
| return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, |
| nb_sectors * BDRV_SECTOR_SIZE); |
| } |
| |
| typedef struct RwCo { |
| BlockDriverState *bs; |
| int64_t sector_num; |
| int nb_sectors; |
| QEMUIOVector *qiov; |
| bool is_write; |
| int ret; |
| } RwCo; |
| |
| static void coroutine_fn bdrv_rw_co_entry(void *opaque) |
| { |
| RwCo *rwco = opaque; |
| |
| if (!rwco->is_write) { |
| rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num, |
| rwco->nb_sectors, rwco->qiov, 0); |
| } else { |
| rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num, |
| rwco->nb_sectors, rwco->qiov, 0); |
| } |
| } |
| |
| /* |
| * Process a synchronous request using coroutines |
| */ |
| static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, |
| int nb_sectors, bool is_write) |
| { |
| QEMUIOVector qiov; |
| struct iovec iov = { |
| .iov_base = (void *)buf, |
| .iov_len = nb_sectors * BDRV_SECTOR_SIZE, |
| }; |
| Coroutine *co; |
| RwCo rwco = { |
| .bs = bs, |
| .sector_num = sector_num, |
| .nb_sectors = nb_sectors, |
| .qiov = &qiov, |
| .is_write = is_write, |
| .ret = NOT_DONE, |
| }; |
| |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| |
| /** |
| * In sync call context, when the vcpu is blocked, this throttling timer |
| * will not fire; so the I/O throttling function has to be disabled here |
| * if it has been enabled. |
| */ |
| if (bs->io_limits_enabled) { |
| fprintf(stderr, "Disabling I/O throttling on '%s' due " |
| "to synchronous I/O.\n", bdrv_get_device_name(bs)); |
| bdrv_io_limits_disable(bs); |
| } |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_rw_co_entry(&rwco); |
| } else { |
| co = qemu_coroutine_create(bdrv_rw_co_entry); |
| qemu_coroutine_enter(co, &rwco); |
| while (rwco.ret == NOT_DONE) { |
| qemu_aio_wait(); |
| } |
| } |
| return rwco.ret; |
| } |
| |
| /* return < 0 if error. See bdrv_write() for the return codes */ |
| int bdrv_read(BlockDriverState *bs, int64_t sector_num, |
| uint8_t *buf, int nb_sectors) |
| { |
| return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false); |
| } |
| |
| /* Just like bdrv_read(), but with I/O throttling temporarily disabled */ |
| int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, |
| uint8_t *buf, int nb_sectors) |
| { |
| bool enabled; |
| int ret; |
| |
| enabled = bs->io_limits_enabled; |
| bs->io_limits_enabled = false; |
| ret = bdrv_read(bs, 0, buf, 1); |
| bs->io_limits_enabled = enabled; |
| return ret; |
| } |
| |
| #define BITS_PER_LONG (sizeof(unsigned long) * 8) |
| |
| static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, int dirty) |
| { |
| int64_t start, end; |
| unsigned long val, idx, bit; |
| |
| start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK; |
| end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK; |
| |
| for (; start <= end; start++) { |
| idx = start / BITS_PER_LONG; |
| bit = start % BITS_PER_LONG; |
| val = bs->dirty_bitmap[idx]; |
| if (dirty) { |
| if (!(val & (1UL << bit))) { |
| bs->dirty_count++; |
| val |= 1UL << bit; |
| } |
| } else { |
| if (val & (1UL << bit)) { |
| bs->dirty_count--; |
| val &= ~(1UL << bit); |
| } |
| } |
| bs->dirty_bitmap[idx] = val; |
| } |
| } |
| |
| /* Return < 0 if error. Important errors are: |
| -EIO generic I/O error (may happen for all errors) |
| -ENOMEDIUM No media inserted. |
| -EINVAL Invalid sector number or nb_sectors |
| -EACCES Trying to write a read-only device |
| */ |
| int bdrv_write(BlockDriverState *bs, int64_t sector_num, |
| const uint8_t *buf, int nb_sectors) |
| { |
| return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true); |
| } |
| |
| int bdrv_pread(BlockDriverState *bs, int64_t offset, |
| void *buf, int count1) |
| { |
| uint8_t tmp_buf[BDRV_SECTOR_SIZE]; |
| int len, nb_sectors, count; |
| int64_t sector_num; |
| int ret; |
| |
| count = count1; |
| /* first read to align to sector start */ |
| len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); |
| if (len > count) |
| len = count; |
| sector_num = offset >> BDRV_SECTOR_BITS; |
| if (len > 0) { |
| if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
| return ret; |
| memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len); |
| count -= len; |
| if (count == 0) |
| return count1; |
| sector_num++; |
| buf += len; |
| } |
| |
| /* read the sectors "in place" */ |
| nb_sectors = count >> BDRV_SECTOR_BITS; |
| if (nb_sectors > 0) { |
| if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0) |
| return ret; |
| sector_num += nb_sectors; |
| len = nb_sectors << BDRV_SECTOR_BITS; |
| buf += len; |
| count -= len; |
| } |
| |
| /* add data from the last sector */ |
| if (count > 0) { |
| if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
| return ret; |
| memcpy(buf, tmp_buf, count); |
| } |
| return count1; |
| } |
| |
| int bdrv_pwrite(BlockDriverState *bs, int64_t offset, |
| const void *buf, int count1) |
| { |
| uint8_t tmp_buf[BDRV_SECTOR_SIZE]; |
| int len, nb_sectors, count; |
| int64_t sector_num; |
| int ret; |
| |
| count = count1; |
| /* first write to align to sector start */ |
| len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); |
| if (len > count) |
| len = count; |
| sector_num = offset >> BDRV_SECTOR_BITS; |
| if (len > 0) { |
| if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
| return ret; |
| memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len); |
| if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) |
| return ret; |
| count -= len; |
| if (count == 0) |
| return count1; |
| sector_num++; |
| buf += len; |
| } |
| |
| /* write the sectors "in place" */ |
| nb_sectors = count >> BDRV_SECTOR_BITS; |
| if (nb_sectors > 0) { |
| if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0) |
| return ret; |
| sector_num += nb_sectors; |
| len = nb_sectors << BDRV_SECTOR_BITS; |
| buf += len; |
| count -= len; |
| } |
| |
| /* add data from the last sector */ |
| if (count > 0) { |
| if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) |
| return ret; |
| memcpy(tmp_buf, buf, count); |
| if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) |
| return ret; |
| } |
| return count1; |
| } |
| |
| /* |
| * Writes to the file and ensures that no writes are reordered across this |
| * request (acts as a barrier) |
| * |
| * Returns 0 on success, -errno in error cases. |
| */ |
| int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, |
| const void *buf, int count) |
| { |
| int ret; |
| |
| ret = bdrv_pwrite(bs, offset, buf, count); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* No flush needed for cache modes that already do it */ |
| if (bs->enable_write_cache) { |
| bdrv_flush(bs); |
| } |
| |
| return 0; |
| } |
| |
| static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) |
| { |
| /* Perform I/O through a temporary buffer so that users who scribble over |
| * their read buffer while the operation is in progress do not end up |
| * modifying the image file. This is critical for zero-copy guest I/O |
| * where anything might happen inside guest memory. |
| */ |
| void *bounce_buffer; |
| |
| BlockDriver *drv = bs->drv; |
| struct iovec iov; |
| QEMUIOVector bounce_qiov; |
| int64_t cluster_sector_num; |
| int cluster_nb_sectors; |
| size_t skip_bytes; |
| int ret; |
| |
| /* Cover entire cluster so no additional backing file I/O is required when |
| * allocating cluster in the image file. |
| */ |
| round_to_clusters(bs, sector_num, nb_sectors, |
| &cluster_sector_num, &cluster_nb_sectors); |
| |
| trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, |
| cluster_sector_num, cluster_nb_sectors); |
| |
| iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; |
| iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len); |
| qemu_iovec_init_external(&bounce_qiov, &iov, 1); |
| |
| ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, |
| &bounce_qiov); |
| if (ret < 0) { |
| goto err; |
| } |
| |
| if (drv->bdrv_co_write_zeroes && |
| buffer_is_zero(bounce_buffer, iov.iov_len)) { |
| ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, |
| cluster_nb_sectors); |
| } else { |
| /* This does not change the data on the disk, it is not necessary |
| * to flush even in cache=writethrough mode. |
| */ |
| ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, |
| &bounce_qiov); |
| } |
| |
| if (ret < 0) { |
| /* It might be okay to ignore write errors for guest requests. If this |
| * is a deliberate copy-on-read then we don't want to ignore the error. |
| * Simply report it in all cases. |
| */ |
| goto err; |
| } |
| |
| skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; |
| qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, |
| nb_sectors * BDRV_SECTOR_SIZE); |
| |
| err: |
| qemu_vfree(bounce_buffer); |
| return ret; |
| } |
| |
| /* |
| * Handle a read request in coroutine context |
| */ |
| static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, |
| BdrvRequestFlags flags) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvTrackedRequest req; |
| int ret; |
| |
| if (!drv) { |
| return -ENOMEDIUM; |
| } |
| if (bdrv_check_request(bs, sector_num, nb_sectors)) { |
| return -EIO; |
| } |
| |
| /* throttling disk read I/O */ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_intercept(bs, false, nb_sectors); |
| } |
| |
| if (bs->copy_on_read) { |
| flags |= BDRV_REQ_COPY_ON_READ; |
| } |
| if (flags & BDRV_REQ_COPY_ON_READ) { |
| bs->copy_on_read_in_flight++; |
| } |
| |
| if (bs->copy_on_read_in_flight) { |
| wait_for_overlapping_requests(bs, sector_num, nb_sectors); |
| } |
| |
| tracked_request_begin(&req, bs, sector_num, nb_sectors, false); |
| |
| if (flags & BDRV_REQ_COPY_ON_READ) { |
| int pnum; |
| |
| ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum); |
| if (ret < 0) { |
| goto out; |
| } |
| |
| if (!ret || pnum != nb_sectors) { |
| ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); |
| goto out; |
| } |
| } |
| |
| ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); |
| |
| out: |
| tracked_request_end(&req); |
| |
| if (flags & BDRV_REQ_COPY_ON_READ) { |
| bs->copy_on_read_in_flight--; |
| } |
| |
| return ret; |
| } |
| |
| int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, QEMUIOVector *qiov) |
| { |
| trace_bdrv_co_readv(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); |
| } |
| |
| int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) |
| { |
| trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, |
| BDRV_REQ_COPY_ON_READ); |
| } |
| |
| static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors) |
| { |
| BlockDriver *drv = bs->drv; |
| QEMUIOVector qiov; |
| struct iovec iov; |
| int ret; |
| |
| /* TODO Emulate only part of misaligned requests instead of letting block |
| * drivers return -ENOTSUP and emulate everything */ |
| |
| /* First try the efficient write zeroes operation */ |
| if (drv->bdrv_co_write_zeroes) { |
| ret = drv->bdrv_co_write_zeroes(bs, sector_num, nb_sectors); |
| if (ret != -ENOTSUP) { |
| return ret; |
| } |
| } |
| |
| /* Fall back to bounce buffer if write zeroes is unsupported */ |
| iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE; |
| iov.iov_base = qemu_blockalign(bs, iov.iov_len); |
| memset(iov.iov_base, 0, iov.iov_len); |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| |
| ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, &qiov); |
| |
| qemu_vfree(iov.iov_base); |
| return ret; |
| } |
| |
| /* |
| * Handle a write request in coroutine context |
| */ |
| static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, |
| BdrvRequestFlags flags) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvTrackedRequest req; |
| int ret; |
| |
| if (!bs->drv) { |
| return -ENOMEDIUM; |
| } |
| if (bs->read_only) { |
| return -EACCES; |
| } |
| if (bdrv_check_request(bs, sector_num, nb_sectors)) { |
| return -EIO; |
| } |
| |
| /* throttling disk write I/O */ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_intercept(bs, true, nb_sectors); |
| } |
| |
| if (bs->copy_on_read_in_flight) { |
| wait_for_overlapping_requests(bs, sector_num, nb_sectors); |
| } |
| |
| tracked_request_begin(&req, bs, sector_num, nb_sectors, true); |
| |
| if (flags & BDRV_REQ_ZERO_WRITE) { |
| ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors); |
| } else { |
| ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); |
| } |
| |
| if (ret == 0 && !bs->enable_write_cache) { |
| ret = bdrv_co_flush(bs); |
| } |
| |
| if (bs->dirty_bitmap) { |
| set_dirty_bitmap(bs, sector_num, nb_sectors, 1); |
| } |
| |
| if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { |
| bs->wr_highest_sector = sector_num + nb_sectors - 1; |
| } |
| |
| tracked_request_end(&req); |
| |
| return ret; |
| } |
| |
| int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, QEMUIOVector *qiov) |
| { |
| trace_bdrv_co_writev(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); |
| } |
| |
| int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors) |
| { |
| trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, |
| BDRV_REQ_ZERO_WRITE); |
| } |
| |
| /** |
| * Truncate file to 'offset' bytes (needed only for file protocols) |
| */ |
| int bdrv_truncate(BlockDriverState *bs, int64_t offset) |
| { |
| BlockDriver *drv = bs->drv; |
| int ret; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_truncate) |
| return -ENOTSUP; |
| if (bs->read_only) |
| return -EACCES; |
| if (bdrv_in_use(bs)) |
| return -EBUSY; |
| ret = drv->bdrv_truncate(bs, offset); |
| if (ret == 0) { |
| ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); |
| bdrv_dev_resize_cb(bs); |
| } |
| return ret; |
| } |
| |
| /** |
| * Length of a allocated file in bytes. Sparse files are counted by actual |
| * allocated space. Return < 0 if error or unknown. |
| */ |
| int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) { |
| return -ENOMEDIUM; |
| } |
| if (drv->bdrv_get_allocated_file_size) { |
| return drv->bdrv_get_allocated_file_size(bs); |
| } |
| if (bs->file) { |
| return bdrv_get_allocated_file_size(bs->file); |
| } |
| return -ENOTSUP; |
| } |
| |
| /** |
| * Length of a file in bytes. Return < 0 if error or unknown. |
| */ |
| int64_t bdrv_getlength(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| |
| if (bs->growable || bdrv_dev_has_removable_media(bs)) { |
| if (drv->bdrv_getlength) { |
| return drv->bdrv_getlength(bs); |
| } |
| } |
| return bs->total_sectors * BDRV_SECTOR_SIZE; |
| } |
| |
| /* return 0 as number of sectors if no device present or error */ |
| void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) |
| { |
| int64_t length; |
| length = bdrv_getlength(bs); |
| if (length < 0) |
| length = 0; |
| else |
| length = length >> BDRV_SECTOR_BITS; |
| *nb_sectors_ptr = length; |
| } |
| |
| /* throttling disk io limits */ |
| void bdrv_set_io_limits(BlockDriverState *bs, |
| BlockIOLimit *io_limits) |
| { |
| bs->io_limits = *io_limits; |
| bs->io_limits_enabled = bdrv_io_limits_enabled(bs); |
| } |
| |
| void bdrv_set_on_error(BlockDriverState *bs, BlockErrorAction on_read_error, |
| BlockErrorAction on_write_error) |
| { |
| bs->on_read_error = on_read_error; |
| bs->on_write_error = on_write_error; |
| } |
| |
| BlockErrorAction bdrv_get_on_error(BlockDriverState *bs, int is_read) |
| { |
| return is_read ? bs->on_read_error : bs->on_write_error; |
| } |
| |
| int bdrv_is_read_only(BlockDriverState *bs) |
| { |
| return bs->read_only; |
| } |
| |
| int bdrv_is_sg(BlockDriverState *bs) |
| { |
| return bs->sg; |
| } |
| |
| int bdrv_enable_write_cache(BlockDriverState *bs) |
| { |
| return bs->enable_write_cache; |
| } |
| |
| void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce) |
| { |
| bs->enable_write_cache = wce; |
| } |
| |
| int bdrv_is_encrypted(BlockDriverState *bs) |
| { |
| if (bs->backing_hd && bs->backing_hd->encrypted) |
| return 1; |
| return bs->encrypted; |
| } |
| |
| int bdrv_key_required(BlockDriverState *bs) |
| { |
| BlockDriverState *backing_hd = bs->backing_hd; |
| |
| if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key) |
| return 1; |
| return (bs->encrypted && !bs->valid_key); |
| } |
| |
| int bdrv_set_key(BlockDriverState *bs, const char *key) |
| { |
| int ret; |
| if (bs->backing_hd && bs->backing_hd->encrypted) { |
| ret = bdrv_set_key(bs->backing_hd, key); |
| if (ret < 0) |
| return ret; |
| if (!bs->encrypted) |
| return 0; |
| } |
| if (!bs->encrypted) { |
| return -EINVAL; |
| } else if (!bs->drv || !bs->drv->bdrv_set_key) { |
| return -ENOMEDIUM; |
| } |
| ret = bs->drv->bdrv_set_key(bs, key); |
| if (ret < 0) { |
| bs->valid_key = 0; |
| } else if (!bs->valid_key) { |
| bs->valid_key = 1; |
| /* call the change callback now, we skipped it on open */ |
| bdrv_dev_change_media_cb(bs, true); |
| } |
| return ret; |
| } |
| |
| const char *bdrv_get_format_name(BlockDriverState *bs) |
| { |
| return bs->drv ? bs->drv->format_name : NULL; |
| } |
| |
| void bdrv_iterate_format(void (*it)(void *opaque, const char *name), |
| void *opaque) |
| { |
| BlockDriver *drv; |
| |
| QLIST_FOREACH(drv, &bdrv_drivers, list) { |
| it(opaque, drv->format_name); |
| } |
| } |
| |
| BlockDriverState *bdrv_find(const char *name) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| if (!strcmp(name, bs->device_name)) { |
| return bs; |
| } |
| } |
| return NULL; |
| } |
| |
| BlockDriverState *bdrv_next(BlockDriverState *bs) |
| { |
| if (!bs) { |
| return QTAILQ_FIRST(&bdrv_states); |
| } |
| return QTAILQ_NEXT(bs, list); |
| } |
| |
| void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| it(opaque, bs); |
| } |
| } |
| |
| const char *bdrv_get_device_name(BlockDriverState *bs) |
| { |
| return bs->device_name; |
| } |
| |
| int bdrv_get_flags(BlockDriverState *bs) |
| { |
| return bs->open_flags; |
| } |
| |
| void bdrv_flush_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| bdrv_flush(bs); |
| } |
| } |
| |
| int bdrv_has_zero_init(BlockDriverState *bs) |
| { |
| assert(bs->drv); |
| |
| if (bs->drv->bdrv_has_zero_init) { |
| return bs->drv->bdrv_has_zero_init(bs); |
| } |
| |
| return 1; |
| } |
| |
| typedef struct BdrvCoIsAllocatedData { |
| BlockDriverState *bs; |
| int64_t sector_num; |
| int nb_sectors; |
| int *pnum; |
| int ret; |
| bool done; |
| } BdrvCoIsAllocatedData; |
| |
| /* |
| * Returns true iff the specified sector is present in the disk image. Drivers |
| * not implementing the functionality are assumed to not support backing files, |
| * hence all their sectors are reported as allocated. |
| * |
| * If 'sector_num' is beyond the end of the disk image the return value is 0 |
| * and 'pnum' is set to 0. |
| * |
| * 'pnum' is set to the number of sectors (including and immediately following |
| * the specified sector) that are known to be in the same |
| * allocated/unallocated state. |
| * |
| * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes |
| * beyond the end of the disk image it will be clamped. |
| */ |
| int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, int *pnum) |
| { |
| int64_t n; |
| |
| if (sector_num >= bs->total_sectors) { |
| *pnum = 0; |
| return 0; |
| } |
| |
| n = bs->total_sectors - sector_num; |
| if (n < nb_sectors) { |
| nb_sectors = n; |
| } |
| |
| if (!bs->drv->bdrv_co_is_allocated) { |
| *pnum = nb_sectors; |
| return 1; |
| } |
| |
| return bs->drv->bdrv_co_is_allocated(bs, sector_num, nb_sectors, pnum); |
| } |
| |
| /* Coroutine wrapper for bdrv_is_allocated() */ |
| static void coroutine_fn bdrv_is_allocated_co_entry(void *opaque) |
| { |
| BdrvCoIsAllocatedData *data = opaque; |
| BlockDriverState *bs = data->bs; |
| |
| data->ret = bdrv_co_is_allocated(bs, data->sector_num, data->nb_sectors, |
| data->pnum); |
| data->done = true; |
| } |
| |
| /* |
| * Synchronous wrapper around bdrv_co_is_allocated(). |
| * |
| * See bdrv_co_is_allocated() for details. |
| */ |
| int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, |
| int *pnum) |
| { |
| Coroutine *co; |
| BdrvCoIsAllocatedData data = { |
| .bs = bs, |
| .sector_num = sector_num, |
| .nb_sectors = nb_sectors, |
| .pnum = pnum, |
| .done = false, |
| }; |
| |
| co = qemu_coroutine_create(bdrv_is_allocated_co_entry); |
| qemu_coroutine_enter(co, &data); |
| while (!data.done) { |
| qemu_aio_wait(); |
| } |
| return data.ret; |
| } |
| |
| /* |
| * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] |
| * |
| * Return true if the given sector is allocated in any image between |
| * BASE and TOP (inclusive). BASE can be NULL to check if the given |
| * sector is allocated in any image of the chain. Return false otherwise. |
| * |
| * 'pnum' is set to the number of sectors (including and immediately following |
| * the specified sector) that are known to be in the same |
| * allocated/unallocated state. |
| * |
| */ |
| int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, |
| BlockDriverState *base, |
| int64_t sector_num, |
| int nb_sectors, int *pnum) |
| { |
| BlockDriverState *intermediate; |
| int ret, n = nb_sectors; |
| |
| intermediate = top; |
| while (intermediate && intermediate != base) { |
| int pnum_inter; |
| ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors, |
| &pnum_inter); |
| if (ret < 0) { |
| return ret; |
| } else if (ret) { |
| *pnum = pnum_inter; |
| return 1; |
| } |
| |
| /* |
| * [sector_num, nb_sectors] is unallocated on top but intermediate |
| * might have |
| * |
| * [sector_num+x, nr_sectors] allocated. |
| */ |
| if (n > pnum_inter) { |
| n = pnum_inter; |
| } |
| |
| intermediate = intermediate->backing_hd; |
| } |
| |
| *pnum = n; |
| return 0; |
| } |
| |
| BlockInfoList *qmp_query_block(Error **errp) |
| { |
| BlockInfoList *head = NULL, *cur_item = NULL; |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| BlockInfoList *info = g_malloc0(sizeof(*info)); |
| |
| info->value = g_malloc0(sizeof(*info->value)); |
| info->value->device = g_strdup(bs->device_name); |
| info->value->type = g_strdup("unknown"); |
| info->value->locked = bdrv_dev_is_medium_locked(bs); |
| info->value->removable = bdrv_dev_has_removable_media(bs); |
| |
| if (bdrv_dev_has_removable_media(bs)) { |
| info->value->has_tray_open = true; |
| info->value->tray_open = bdrv_dev_is_tray_open(bs); |
| } |
| |
| if (bdrv_iostatus_is_enabled(bs)) { |
| info->value->has_io_status = true; |
| info->value->io_status = bs->iostatus; |
| } |
| |
| if (bs->drv) { |
| info->value->has_inserted = true; |
| info->value->inserted = g_malloc0(sizeof(*info->value->inserted)); |
| info->value->inserted->file = g_strdup(bs->filename); |
| info->value->inserted->ro = bs->read_only; |
| info->value->inserted->drv = g_strdup(bs->drv->format_name); |
| info->value->inserted->encrypted = bs->encrypted; |
| if (bs->backing_file[0]) { |
| info->value->inserted->has_backing_file = true; |
| info->value->inserted->backing_file = g_strdup(bs->backing_file); |
| } |
| |
| if (bs->io_limits_enabled) { |
| info->value->inserted->bps = |
| bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]; |
| info->value->inserted->bps_rd = |
| bs->io_limits.bps[BLOCK_IO_LIMIT_READ]; |
| info->value->inserted->bps_wr = |
| bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE]; |
| info->value->inserted->iops = |
| bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]; |
| info->value->inserted->iops_rd = |
| bs->io_limits.iops[BLOCK_IO_LIMIT_READ]; |
| info->value->inserted->iops_wr = |
| bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE]; |
| } |
| } |
| |
| /* XXX: waiting for the qapi to support GSList */ |
| if (!cur_item) { |
| head = cur_item = info; |
| } else { |
| cur_item->next = info; |
| cur_item = info; |
| } |
| } |
| |
| return head; |
| } |
| |
| /* Consider exposing this as a full fledged QMP command */ |
| static BlockStats *qmp_query_blockstat(const BlockDriverState *bs, Error **errp) |
| { |
| BlockStats *s; |
| |
| s = g_malloc0(sizeof(*s)); |
| |
| if (bs->device_name[0]) { |
| s->has_device = true; |
| s->device = g_strdup(bs->device_name); |
| } |
| |
| s->stats = g_malloc0(sizeof(*s->stats)); |
| s->stats->rd_bytes = bs->nr_bytes[BDRV_ACCT_READ]; |
| s->stats->wr_bytes = bs->nr_bytes[BDRV_ACCT_WRITE]; |
| s->stats->rd_operations = bs->nr_ops[BDRV_ACCT_READ]; |
| s->stats->wr_operations = bs->nr_ops[BDRV_ACCT_WRITE]; |
| s->stats->wr_highest_offset = bs->wr_highest_sector * BDRV_SECTOR_SIZE; |
| s->stats->flush_operations = bs->nr_ops[BDRV_ACCT_FLUSH]; |
| s->stats->wr_total_time_ns = bs->total_time_ns[BDRV_ACCT_WRITE]; |
| s->stats->rd_total_time_ns = bs->total_time_ns[BDRV_ACCT_READ]; |
| s->stats->flush_total_time_ns = bs->total_time_ns[BDRV_ACCT_FLUSH]; |
| |
| if (bs->file) { |
| s->has_parent = true; |
| s->parent = qmp_query_blockstat(bs->file, NULL); |
| } |
| |
| return s; |
| } |
| |
| BlockStatsList *qmp_query_blockstats(Error **errp) |
| { |
| BlockStatsList *head = NULL, *cur_item = NULL; |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| BlockStatsList *info = g_malloc0(sizeof(*info)); |
| info->value = qmp_query_blockstat(bs, NULL); |
| |
| /* XXX: waiting for the qapi to support GSList */ |
| if (!cur_item) { |
| head = cur_item = info; |
| } else { |
| cur_item->next = info; |
| cur_item = info; |
| } |
| } |
| |
| return head; |
| } |
| |
| const char *bdrv_get_encrypted_filename(BlockDriverState *bs) |
| { |
| if (bs->backing_hd && bs->backing_hd->encrypted) |
| return bs->backing_file; |
| else if (bs->encrypted) |
| return bs->filename; |
| else |
| return NULL; |
| } |
| |
| void bdrv_get_backing_filename(BlockDriverState *bs, |
| char *filename, int filename_size) |
| { |
| pstrcpy(filename, filename_size, bs->backing_file); |
| } |
| |
| int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, |
| const uint8_t *buf, int nb_sectors) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_write_compressed) |
| return -ENOTSUP; |
| if (bdrv_check_request(bs, sector_num, nb_sectors)) |
| return -EIO; |
| |
| if (bs->dirty_bitmap) { |
| set_dirty_bitmap(bs, sector_num, nb_sectors, 1); |
| } |
| |
| return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); |
| } |
| |
| int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_get_info) |
| return -ENOTSUP; |
| memset(bdi, 0, sizeof(*bdi)); |
| return drv->bdrv_get_info(bs, bdi); |
| } |
| |
| int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
| int64_t pos, int size) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_save_vmstate) |
| return drv->bdrv_save_vmstate(bs, buf, pos, size); |
| if (bs->file) |
| return bdrv_save_vmstate(bs->file, buf, pos, size); |
| return -ENOTSUP; |
| } |
| |
| int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
| int64_t pos, int size) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_load_vmstate) |
| return drv->bdrv_load_vmstate(bs, buf, pos, size); |
| if (bs->file) |
| return bdrv_load_vmstate(bs->file, buf, pos, size); |
| return -ENOTSUP; |
| } |
| |
| void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (!drv || !drv->bdrv_debug_event) { |
| return; |
| } |
| |
| drv->bdrv_debug_event(bs, event); |
| |
| } |
| |
| /**************************************************************/ |
| /* handling of snapshots */ |
| |
| int bdrv_can_snapshot(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { |
| return 0; |
| } |
| |
| if (!drv->bdrv_snapshot_create) { |
| if (bs->file != NULL) { |
| return bdrv_can_snapshot(bs->file); |
| } |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| int bdrv_is_snapshot(BlockDriverState *bs) |
| { |
| return !!(bs->open_flags & BDRV_O_SNAPSHOT); |
| } |
| |
| BlockDriverState *bdrv_snapshots(void) |
| { |
| BlockDriverState *bs; |
| |
| if (bs_snapshots) { |
| return bs_snapshots; |
| } |
| |
| bs = NULL; |
| while ((bs = bdrv_next(bs))) { |
| if (bdrv_can_snapshot(bs)) { |
| bs_snapshots = bs; |
| return bs; |
| } |
| } |
| return NULL; |
| } |
| |
| int bdrv_snapshot_create(BlockDriverState *bs, |
| QEMUSnapshotInfo *sn_info) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_snapshot_create) |
| return drv->bdrv_snapshot_create(bs, sn_info); |
| if (bs->file) |
| return bdrv_snapshot_create(bs->file, sn_info); |
| return -ENOTSUP; |
| } |
| |
| int bdrv_snapshot_goto(BlockDriverState *bs, |
| const char *snapshot_id) |
| { |
| BlockDriver *drv = bs->drv; |
| int ret, open_ret; |
| |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_snapshot_goto) |
| return drv->bdrv_snapshot_goto(bs, snapshot_id); |
| |
| if (bs->file) { |
| drv->bdrv_close(bs); |
| ret = bdrv_snapshot_goto(bs->file, snapshot_id); |
| open_ret = drv->bdrv_open(bs, bs->open_flags); |
| if (open_ret < 0) { |
| bdrv_delete(bs->file); |
| bs->drv = NULL; |
| return open_ret; |
| } |
| return ret; |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_snapshot_delete) |
| return drv->bdrv_snapshot_delete(bs, snapshot_id); |
| if (bs->file) |
| return bdrv_snapshot_delete(bs->file, snapshot_id); |
| return -ENOTSUP; |
| } |
| |
| int bdrv_snapshot_list(BlockDriverState *bs, |
| QEMUSnapshotInfo **psn_info) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_snapshot_list) |
| return drv->bdrv_snapshot_list(bs, psn_info); |
| if (bs->file) |
| return bdrv_snapshot_list(bs->file, psn_info); |
| return -ENOTSUP; |
| } |
| |
| int bdrv_snapshot_load_tmp(BlockDriverState *bs, |
| const char *snapshot_name) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) { |
| return -ENOMEDIUM; |
| } |
| if (!bs->read_only) { |
| return -EINVAL; |
| } |
| if (drv->bdrv_snapshot_load_tmp) { |
| return drv->bdrv_snapshot_load_tmp(bs, snapshot_name); |
| } |
| return -ENOTSUP; |
| } |
| |
| BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, |
| const char *backing_file) |
| { |
| if (!bs->drv) { |
| return NULL; |
| } |
| |
| if (bs->backing_hd) { |
| if (strcmp(bs->backing_file, backing_file) == 0) { |
| return bs->backing_hd; |
| } else { |
| return bdrv_find_backing_image(bs->backing_hd, backing_file); |
| } |
| } |
| |
| return NULL; |
| } |
| |
| #define NB_SUFFIXES 4 |
| |
| char *get_human_readable_size(char *buf, int buf_size, int64_t size) |
| { |
| static const char suffixes[NB_SUFFIXES] = "KMGT"; |
| int64_t base; |
| int i; |
| |
| if (size <= 999) { |
| snprintf(buf, buf_size, "%" PRId64, size); |
| } else { |
| base = 1024; |
| for(i = 0; i < NB_SUFFIXES; i++) { |
| if (size < (10 * base)) { |
| snprintf(buf, buf_size, "%0.1f%c", |
| (double)size / base, |
| suffixes[i]); |
| break; |
| } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) { |
| snprintf(buf, buf_size, "%" PRId64 "%c", |
| ((size + (base >> 1)) / base), |
| suffixes[i]); |
| break; |
| } |
| base = base * 1024; |
| } |
| } |
| return buf; |
| } |
| |
| char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn) |
| { |
| char buf1[128], date_buf[128], clock_buf[128]; |
| #ifdef _WIN32 |
| struct tm *ptm; |
| #else |
| struct tm tm; |
| #endif |
| time_t ti; |
| int64_t secs; |
| |
| if (!sn) { |
| snprintf(buf, buf_size, |
| "%-10s%-20s%7s%20s%15s", |
| "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK"); |
| } else { |
| ti = sn->date_sec; |
| #ifdef _WIN32 |
| ptm = localtime(&ti); |
| strftime(date_buf, sizeof(date_buf), |
| "%Y-%m-%d %H:%M:%S", ptm); |
| #else |
| localtime_r(&ti, &tm); |
| strftime(date_buf, sizeof(date_buf), |
| "%Y-%m-%d %H:%M:%S", &tm); |
| #endif |
| secs = sn->vm_clock_nsec / 1000000000; |
| snprintf(clock_buf, sizeof(clock_buf), |
| "%02d:%02d:%02d.%03d", |
| (int)(secs / 3600), |
| (int)((secs / 60) % 60), |
| (int)(secs % 60), |
| (int)((sn->vm_clock_nsec / 1000000) % 1000)); |
| snprintf(buf, buf_size, |
| "%-10s%-20s%7s%20s%15s", |
| sn->id_str, sn->name, |
| get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size), |
| date_buf, |
| clock_buf); |
| } |
| return buf; |
| } |
| |
| /**************************************************************/ |
| /* async I/Os */ |
| |
| BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, |
| QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); |
| |
| return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, |
| cb, opaque, false); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, |
| QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); |
| |
| return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, |
| cb, opaque, true); |
| } |
| |
| |
| typedef struct MultiwriteCB { |
| int error; |
| int num_requests; |
| int num_callbacks; |
| struct { |
| BlockDriverCompletionFunc *cb; |
| void *opaque; |
| QEMUIOVector *free_qiov; |
| } callbacks[]; |
| } MultiwriteCB; |
| |
| static void multiwrite_user_cb(MultiwriteCB *mcb) |
| { |
| int i; |
| |
| for (i = 0; i < mcb->num_callbacks; i++) { |
| mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); |
| if (mcb->callbacks[i].free_qiov) { |
| qemu_iovec_destroy(mcb->callbacks[i].free_qiov); |
| } |
| g_free(mcb->callbacks[i].free_qiov); |
| } |
| } |
| |
| static void multiwrite_cb(void *opaque, int ret) |
| { |
| MultiwriteCB *mcb = opaque; |
| |
| trace_multiwrite_cb(mcb, ret); |
| |
| if (ret < 0 && !mcb->error) { |
| mcb->error = ret; |
| } |
| |
| mcb->num_requests--; |
| if (mcb->num_requests == 0) { |
| multiwrite_user_cb(mcb); |
| g_free(mcb); |
| } |
| } |
| |
| static int multiwrite_req_compare(const void *a, const void *b) |
| { |
| const BlockRequest *req1 = a, *req2 = b; |
| |
| /* |
| * Note that we can't simply subtract req2->sector from req1->sector |
| * here as that could overflow the return value. |
| */ |
| if (req1->sector > req2->sector) { |
| return 1; |
| } else if (req1->sector < req2->sector) { |
| return -1; |
| } else { |
| return 0; |
| } |
| } |
| |
| /* |
| * Takes a bunch of requests and tries to merge them. Returns the number of |
| * requests that remain after merging. |
| */ |
| static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, |
| int num_reqs, MultiwriteCB *mcb) |
| { |
| int i, outidx; |
| |
| // Sort requests by start sector |
| qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); |
| |
| // Check if adjacent requests touch the same clusters. If so, combine them, |
| // filling up gaps with zero sectors. |
| outidx = 0; |
| for (i = 1; i < num_reqs; i++) { |
| int merge = 0; |
| int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; |
| |
| // Handle exactly sequential writes and overlapping writes. |
| if (reqs[i].sector <= oldreq_last) { |
| merge = 1; |
| } |
| |
| if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { |
| merge = 0; |
| } |
| |
| if (merge) { |
| size_t size; |
| QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); |
| qemu_iovec_init(qiov, |
| reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); |
| |
| // Add the first request to the merged one. If the requests are |
| // overlapping, drop the last sectors of the first request. |
| size = (reqs[i].sector - reqs[outidx].sector) << 9; |
| qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); |
| |
| // We should need to add any zeros between the two requests |
| assert (reqs[i].sector <= oldreq_last); |
| |
| // Add the second request |
| qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); |
| |
| reqs[outidx].nb_sectors = qiov->size >> 9; |
| reqs[outidx].qiov = qiov; |
| |
| mcb->callbacks[i].free_qiov = reqs[outidx].qiov; |
| } else { |
| outidx++; |
| reqs[outidx].sector = reqs[i].sector; |
| reqs[outidx].nb_sectors = reqs[i].nb_sectors; |
| reqs[outidx].qiov = reqs[i].qiov; |
| } |
| } |
| |
| return outidx + 1; |
| } |
| |
| /* |
| * Submit multiple AIO write requests at once. |
| * |
| * On success, the function returns 0 and all requests in the reqs array have |
| * been submitted. In error case this function returns -1, and any of the |
| * requests may or may not be submitted yet. In particular, this means that the |
| * callback will be called for some of the requests, for others it won't. The |
| * caller must check the error field of the BlockRequest to wait for the right |
| * callbacks (if error != 0, no callback will be called). |
| * |
| * The implementation may modify the contents of the reqs array, e.g. to merge |
| * requests. However, the fields opaque and error are left unmodified as they |
| * are used to signal failure for a single request to the caller. |
| */ |
| int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) |
| { |
| MultiwriteCB *mcb; |
| int i; |
| |
| /* don't submit writes if we don't have a medium */ |
| if (bs->drv == NULL) { |
| for (i = 0; i < num_reqs; i++) { |
| reqs[i].error = -ENOMEDIUM; |
| } |
| return -1; |
| } |
| |
| if (num_reqs == 0) { |
| return 0; |
| } |
| |
| // Create MultiwriteCB structure |
| mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); |
| mcb->num_requests = 0; |
| mcb->num_callbacks = num_reqs; |
| |
| for (i = 0; i < num_reqs; i++) { |
| mcb->callbacks[i].cb = reqs[i].cb; |
| mcb->callbacks[i].opaque = reqs[i].opaque; |
| } |
| |
| // Check for mergable requests |
| num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); |
| |
| trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); |
| |
| /* Run the aio requests. */ |
| mcb->num_requests = num_reqs; |
| for (i = 0; i < num_reqs; i++) { |
| bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov, |
| reqs[i].nb_sectors, multiwrite_cb, mcb); |
| } |
| |
| return 0; |
| } |
| |
| void bdrv_aio_cancel(BlockDriverAIOCB *acb) |
| { |
| acb->pool->cancel(acb); |
| } |
| |
| /* block I/O throttling */ |
| static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors, |
| bool is_write, double elapsed_time, uint64_t *wait) |
| { |
| uint64_t bps_limit = 0; |
| double bytes_limit, bytes_base, bytes_res; |
| double slice_time, wait_time; |
| |
| if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { |
| bps_limit = bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]; |
| } else if (bs->io_limits.bps[is_write]) { |
| bps_limit = bs->io_limits.bps[is_write]; |
| } else { |
| if (wait) { |
| *wait = 0; |
| } |
| |
| return false; |
| } |
| |
| slice_time = bs->slice_end - bs->slice_start; |
| slice_time /= (NANOSECONDS_PER_SECOND); |
| bytes_limit = bps_limit * slice_time; |
| bytes_base = bs->nr_bytes[is_write] - bs->io_base.bytes[is_write]; |
| if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { |
| bytes_base += bs->nr_bytes[!is_write] - bs->io_base.bytes[!is_write]; |
| } |
| |
| /* bytes_base: the bytes of data which have been read/written; and |
| * it is obtained from the history statistic info. |
| * bytes_res: the remaining bytes of data which need to be read/written. |
| * (bytes_base + bytes_res) / bps_limit: used to calcuate |
| * the total time for completing reading/writting all data. |
| */ |
| bytes_res = (unsigned) nb_sectors * BDRV_SECTOR_SIZE; |
| |
| if (bytes_base + bytes_res <= bytes_limit) { |
| if (wait) { |
| *wait = 0; |
| } |
| |
| return false; |
| } |
| |
| /* Calc approx time to dispatch */ |
| wait_time = (bytes_base + bytes_res) / bps_limit - elapsed_time; |
| |
| /* When the I/O rate at runtime exceeds the limits, |
| * bs->slice_end need to be extended in order that the current statistic |
| * info can be kept until the timer fire, so it is increased and tuned |
| * based on the result of experiment. |
| */ |
| bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10; |
| bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME; |
| if (wait) { |
| *wait = wait_time * BLOCK_IO_SLICE_TIME * 10; |
| } |
| |
| return true; |
| } |
| |
| static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write, |
| double elapsed_time, uint64_t *wait) |
| { |
| uint64_t iops_limit = 0; |
| double ios_limit, ios_base; |
| double slice_time, wait_time; |
| |
| if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { |
| iops_limit = bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]; |
| } else if (bs->io_limits.iops[is_write]) { |
| iops_limit = bs->io_limits.iops[is_write]; |
| } else { |
| if (wait) { |
| *wait = 0; |
| } |
| |
| return false; |
| } |
| |
| slice_time = bs->slice_end - bs->slice_start; |
| slice_time /= (NANOSECONDS_PER_SECOND); |
| ios_limit = iops_limit * slice_time; |
| ios_base = bs->nr_ops[is_write] - bs->io_base.ios[is_write]; |
| if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { |
| ios_base += bs->nr_ops[!is_write] - bs->io_base.ios[!is_write]; |
| } |
| |
| if (ios_base + 1 <= ios_limit) { |
| if (wait) { |
| *wait = 0; |
| } |
| |
| return false; |
| } |
| |
| /* Calc approx time to dispatch */ |
| wait_time = (ios_base + 1) / iops_limit; |
| if (wait_time > elapsed_time) { |
| wait_time = wait_time - elapsed_time; |
| } else { |
| wait_time = 0; |
| } |
| |
| bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10; |
| bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME; |
| if (wait) { |
| *wait = wait_time * BLOCK_IO_SLICE_TIME * 10; |
| } |
| |
| return true; |
| } |
| |
| static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors, |
| bool is_write, int64_t *wait) |
| { |
| int64_t now, max_wait; |
| uint64_t bps_wait = 0, iops_wait = 0; |
| double elapsed_time; |
| int bps_ret, iops_ret; |
| |
| now = qemu_get_clock_ns(vm_clock); |
| if ((bs->slice_start < now) |
| && (bs->slice_end > now)) { |
| bs->slice_end = now + bs->slice_time; |
| } else { |
| bs->slice_time = 5 * BLOCK_IO_SLICE_TIME; |
| bs->slice_start = now; |
| bs->slice_end = now + bs->slice_time; |
| |
| bs->io_base.bytes[is_write] = bs->nr_bytes[is_write]; |
| bs->io_base.bytes[!is_write] = bs->nr_bytes[!is_write]; |
| |
| bs->io_base.ios[is_write] = bs->nr_ops[is_write]; |
| bs->io_base.ios[!is_write] = bs->nr_ops[!is_write]; |
| } |
| |
| elapsed_time = now - bs->slice_start; |
| elapsed_time /= (NANOSECONDS_PER_SECOND); |
| |
| bps_ret = bdrv_exceed_bps_limits(bs, nb_sectors, |
| is_write, elapsed_time, &bps_wait); |
| iops_ret = bdrv_exceed_iops_limits(bs, is_write, |
| elapsed_time, &iops_wait); |
| if (bps_ret || iops_ret) { |
| max_wait = bps_wait > iops_wait ? bps_wait : iops_wait; |
| if (wait) { |
| *wait = max_wait; |
| } |
| |
| now = qemu_get_clock_ns(vm_clock); |
| if (bs->slice_end < now + max_wait) { |
| bs->slice_end = now + max_wait; |
| } |
| |
| return true; |
| } |
| |
| if (wait) { |
| *wait = 0; |
| } |
| |
| return false; |
| } |
| |
| /**************************************************************/ |
| /* async block device emulation */ |
| |
| typedef struct BlockDriverAIOCBSync { |
| BlockDriverAIOCB common; |
| QEMUBH *bh; |
| int ret; |
| /* vector translation state */ |
| QEMUIOVector *qiov; |
| uint8_t *bounce; |
| int is_write; |
| } BlockDriverAIOCBSync; |
| |
| static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) |
| { |
| BlockDriverAIOCBSync *acb = |
| container_of(blockacb, BlockDriverAIOCBSync, common); |
| qemu_bh_delete(acb->bh); |
| acb->bh = NULL; |
| qemu_aio_release(acb); |
| } |
| |
| static AIOPool bdrv_em_aio_pool = { |
| .aiocb_size = sizeof(BlockDriverAIOCBSync), |
| .cancel = bdrv_aio_cancel_em, |
| }; |
| |
| static void bdrv_aio_bh_cb(void *opaque) |
| { |
| BlockDriverAIOCBSync *acb = opaque; |
| |
| if (!acb->is_write) |
| qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); |
| qemu_vfree(acb->bounce); |
| acb->common.cb(acb->common.opaque, acb->ret); |
| qemu_bh_delete(acb->bh); |
| acb->bh = NULL; |
| qemu_aio_release(acb); |
| } |
| |
| static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, |
| int64_t sector_num, |
| QEMUIOVector *qiov, |
| int nb_sectors, |
| BlockDriverCompletionFunc *cb, |
| void *opaque, |
| int is_write) |
| |
| { |
| BlockDriverAIOCBSync *acb; |
| |
| acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque); |
| acb->is_write = is_write; |
| acb->qiov = qiov; |
| acb->bounce = qemu_blockalign(bs, qiov->size); |
| acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); |
| |
| if (is_write) { |
| qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); |
| acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); |
| } else { |
| acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); |
| } |
| |
| qemu_bh_schedule(acb->bh); |
| |
| return &acb->common; |
| } |
| |
| static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); |
| } |
| |
| static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); |
| } |
| |
| |
| typedef struct BlockDriverAIOCBCoroutine { |
| BlockDriverAIOCB common; |
| BlockRequest req; |
| bool is_write; |
| QEMUBH* bh; |
| } BlockDriverAIOCBCoroutine; |
| |
| static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb) |
| { |
| qemu_aio_flush(); |
| } |
| |
| static AIOPool bdrv_em_co_aio_pool = { |
| .aiocb_size = sizeof(BlockDriverAIOCBCoroutine), |
| .cancel = bdrv_aio_co_cancel_em, |
| }; |
| |
| static void bdrv_co_em_bh(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| |
| acb->common.cb(acb->common.opaque, acb->req.error); |
| qemu_bh_delete(acb->bh); |
| qemu_aio_release(acb); |
| } |
| |
| /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ |
| static void coroutine_fn bdrv_co_do_rw(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| BlockDriverState *bs = acb->common.bs; |
| |
| if (!acb->is_write) { |
| acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, |
| acb->req.nb_sectors, acb->req.qiov, 0); |
| } else { |
| acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, |
| acb->req.nb_sectors, acb->req.qiov, 0); |
| } |
| |
| acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); |
| qemu_bh_schedule(acb->bh); |
| } |
| |
| static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, |
| int64_t sector_num, |
| QEMUIOVector *qiov, |
| int nb_sectors, |
| BlockDriverCompletionFunc *cb, |
| void *opaque, |
| bool is_write) |
| { |
| Coroutine *co; |
| BlockDriverAIOCBCoroutine *acb; |
| |
| acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque); |
| acb->req.sector = sector_num; |
| acb->req.nb_sectors = nb_sectors; |
| acb->req.qiov = qiov; |
| acb->is_write = is_write; |
| |
| co = qemu_coroutine_create(bdrv_co_do_rw); |
| qemu_coroutine_enter(co, acb); |
| |
| return &acb->common; |
| } |
| |
| static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| BlockDriverState *bs = acb->common.bs; |
| |
| acb->req.error = bdrv_co_flush(bs); |
| acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); |
| qemu_bh_schedule(acb->bh); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_flush(bs, opaque); |
| |
| Coroutine *co; |
| BlockDriverAIOCBCoroutine *acb; |
| |
| acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque); |
| co = qemu_coroutine_create(bdrv_aio_flush_co_entry); |
| qemu_coroutine_enter(co, acb); |
| |
| return &acb->common; |
| } |
| |
| static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| BlockDriverState *bs = acb->common.bs; |
| |
| acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); |
| acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); |
| qemu_bh_schedule(acb->bh); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| Coroutine *co; |
| BlockDriverAIOCBCoroutine *acb; |
| |
| trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); |
| |
| acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque); |
| acb->req.sector = sector_num; |
| acb->req.nb_sectors = nb_sectors; |
| co = qemu_coroutine_create(bdrv_aio_discard_co_entry); |
| qemu_coroutine_enter(co, acb); |
| |
| return &acb->common; |
| } |
| |
| void bdrv_init(void) |
| { |
| module_call_init(MODULE_INIT_BLOCK); |
| } |
| |
| void bdrv_init_with_whitelist(void) |
| { |
| use_bdrv_whitelist = 1; |
| bdrv_init(); |
| } |
| |
| void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| BlockDriverAIOCB *acb; |
| |
| if (pool->free_aiocb) { |
| acb = pool->free_aiocb; |
| pool->free_aiocb = acb->next; |
| } else { |
| acb = g_malloc0(pool->aiocb_size); |
| acb->pool = pool; |
| } |
| acb->bs = bs; |
| acb->cb = cb; |
| acb->opaque = opaque; |
| return acb; |
| } |
| |
| void qemu_aio_release(void *p) |
| { |
| BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p; |
| AIOPool *pool = acb->pool; |
| acb->next = pool->free_aiocb; |
| pool->free_aiocb = acb; |
| } |
| |
| /**************************************************************/ |
| /* Coroutine block device emulation */ |
| |
| typedef struct CoroutineIOCompletion { |
| Coroutine *coroutine; |
| int ret; |
| } CoroutineIOCompletion; |
| |
| static void bdrv_co_io_em_complete(void *opaque, int ret) |
| { |
| CoroutineIOCompletion *co = opaque; |
| |
| co->ret = ret; |
| qemu_coroutine_enter(co->coroutine, NULL); |
| } |
| |
| static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, QEMUIOVector *iov, |
| bool is_write) |
| { |
| CoroutineIOCompletion co = { |
| .coroutine = qemu_coroutine_self(), |
| }; |
| BlockDriverAIOCB *acb; |
| |
| if (is_write) { |
| acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, |
| bdrv_co_io_em_complete, &co); |
| } else { |
| acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, |
| bdrv_co_io_em_complete, &co); |
| } |
| |
| trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); |
| if (!acb) { |
| return -EIO; |
| } |
| qemu_coroutine_yield(); |
| |
| return co.ret; |
| } |
| |
| static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov) |
| { |
| return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); |
| } |
| |
| static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov) |
| { |
| return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); |
| } |
| |
| static void coroutine_fn bdrv_flush_co_entry(void *opaque) |
| { |
| RwCo *rwco = opaque; |
| |
| rwco->ret = bdrv_co_flush(rwco->bs); |
| } |
| |
| int coroutine_fn bdrv_co_flush(BlockDriverState *bs) |
| { |
| int ret; |
| |
| if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { |
| return 0; |
| } |
| |
| /* Write back cached data to the OS even with cache=unsafe */ |
| if (bs->drv->bdrv_co_flush_to_os) { |
| ret = bs->drv->bdrv_co_flush_to_os(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| /* But don't actually force it to the disk with cache=unsafe */ |
| if (bs->open_flags & BDRV_O_NO_FLUSH) { |
| return 0; |
| } |
| |
| if (bs->drv->bdrv_co_flush_to_disk) { |
| ret = bs->drv->bdrv_co_flush_to_disk(bs); |
| } else if (bs->drv->bdrv_aio_flush) { |
| BlockDriverAIOCB *acb; |
| CoroutineIOCompletion co = { |
| .coroutine = qemu_coroutine_self(), |
| }; |
| |
| acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); |
| if (acb == NULL) { |
| ret = -EIO; |
| } else { |
| qemu_coroutine_yield(); |
| ret = co.ret; |
| } |
| } else { |
| /* |
| * Some block drivers always operate in either writethrough or unsafe |
| * mode and don't support bdrv_flush therefore. Usually qemu doesn't |
| * know how the server works (because the behaviour is hardcoded or |
| * depends on server-side configuration), so we can't ensure that |
| * everything is safe on disk. Returning an error doesn't work because |
| * that would break guests even if the server operates in writethrough |
| * mode. |
| * |
| * Let's hope the user knows what he's doing. |
| */ |
| ret = 0; |
| } |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH |
| * in the case of cache=unsafe, so there are no useless flushes. |
| */ |
| return bdrv_co_flush(bs->file); |
| } |
| |
| void bdrv_invalidate_cache(BlockDriverState *bs) |
| { |
| if (bs->drv && bs->drv->bdrv_invalidate_cache) { |
| bs->drv->bdrv_invalidate_cache(bs); |
| } |
| } |
| |
| void bdrv_invalidate_cache_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| bdrv_invalidate_cache(bs); |
| } |
| } |
| |
| void bdrv_clear_incoming_migration_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, list) { |
| bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); |
| } |
| } |
| |
| int bdrv_flush(BlockDriverState *bs) |
| { |
| Coroutine *co; |
| RwCo rwco = { |
| .bs = bs, |
| .ret = NOT_DONE, |
| }; |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_flush_co_entry(&rwco); |
| } else { |
| co = qemu_coroutine_create(bdrv_flush_co_entry); |
| qemu_coroutine_enter(co, &rwco); |
| while (rwco.ret == NOT_DONE) { |
| qemu_aio_wait(); |
| } |
| } |
| |
| return rwco.ret; |
| } |
| |
| static void coroutine_fn bdrv_discard_co_entry(void *opaque) |
| { |
| RwCo *rwco = opaque; |
| |
| rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); |
| } |
| |
| int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors) |
| { |
| if (!bs->drv) { |
| return -ENOMEDIUM; |
| } else if (bdrv_check_request(bs, sector_num, nb_sectors)) { |
| return -EIO; |
| } else if (bs->read_only) { |
| return -EROFS; |
| } else if (bs->drv->bdrv_co_discard) { |
| return bs->drv->bdrv_co_discard(bs, sector_num, nb_sectors); |
| } else if (bs->drv->bdrv_aio_discard) { |
| BlockDriverAIOCB *acb; |
| CoroutineIOCompletion co = { |
| .coroutine = qemu_coroutine_self(), |
| }; |
| |
| acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, |
| bdrv_co_io_em_complete, &co); |
| if (acb == NULL) { |
| return -EIO; |
| } else { |
| qemu_coroutine_yield(); |
| return co.ret; |
| } |
| } else { |
| return 0; |
| } |
| } |
| |
| int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) |
| { |
| Coroutine *co; |
| RwCo rwco = { |
| .bs = bs, |
| .sector_num = sector_num, |
| .nb_sectors = nb_sectors, |
| .ret = NOT_DONE, |
| }; |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_discard_co_entry(&rwco); |
| } else { |
| co = qemu_coroutine_create(bdrv_discard_co_entry); |
| qemu_coroutine_enter(co, &rwco); |
| while (rwco.ret == NOT_DONE) { |
| qemu_aio_wait(); |
| } |
| } |
| |
| return rwco.ret; |
| } |
| |
| /**************************************************************/ |
| /* removable device support */ |
| |
| /** |
| * Return TRUE if the media is present |
| */ |
| int bdrv_is_inserted(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (!drv) |
| return 0; |
| if (!drv->bdrv_is_inserted) |
| return 1; |
| return drv->bdrv_is_inserted(bs); |
| } |
| |
| /** |
| * Return whether the media changed since the last call to this |
| * function, or -ENOTSUP if we don't know. Most drivers don't know. |
| */ |
| int bdrv_media_changed(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_media_changed) { |
| return drv->bdrv_media_changed(bs); |
| } |
| return -ENOTSUP; |
| } |
| |
| /** |
| * If eject_flag is TRUE, eject the media. Otherwise, close the tray |
| */ |
| void bdrv_eject(BlockDriverState *bs, bool eject_flag) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_eject) { |
| drv->bdrv_eject(bs, eject_flag); |
| } |
| |
| if (bs->device_name[0] != '\0') { |
| bdrv_emit_qmp_eject_event(bs, eject_flag); |
| } |
| } |
| |
| /** |
| * Lock or unlock the media (if it is locked, the user won't be able |
| * to eject it manually). |
| */ |
| void bdrv_lock_medium(BlockDriverState *bs, bool locked) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| trace_bdrv_lock_medium(bs, locked); |
| |
| if (drv && drv->bdrv_lock_medium) { |
| drv->bdrv_lock_medium(bs, locked); |
| } |
| } |
| |
| /* needed for generic scsi interface */ |
| |
| int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_ioctl) |
| return drv->bdrv_ioctl(bs, req, buf); |
| return -ENOTSUP; |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, |
| unsigned long int req, void *buf, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_aio_ioctl) |
| return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); |
| return NULL; |
| } |
| |
| void bdrv_set_buffer_alignment(BlockDriverState *bs, int align) |
| { |
| bs->buffer_alignment = align; |
| } |
| |
| void *qemu_blockalign(BlockDriverState *bs, size_t size) |
| { |
| return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size); |
| } |
| |
| void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable) |
| { |
| int64_t bitmap_size; |
| |
| bs->dirty_count = 0; |
| if (enable) { |
| if (!bs->dirty_bitmap) { |
| bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) + |
| BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1; |
| bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG; |
| |
| bs->dirty_bitmap = g_new0(unsigned long, bitmap_size); |
| } |
| } else { |
| if (bs->dirty_bitmap) { |
| g_free(bs->dirty_bitmap); |
| bs->dirty_bitmap = NULL; |
| } |
| } |
| } |
| |
| int bdrv_get_dirty(BlockDriverState *bs, int64_t sector) |
| { |
| int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK; |
| |
| if (bs->dirty_bitmap && |
| (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) { |
| return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] & |
| (1UL << (chunk % (sizeof(unsigned long) * 8)))); |
| } else { |
| return 0; |
| } |
| } |
| |
| void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, |
| int nr_sectors) |
| { |
| set_dirty_bitmap(bs, cur_sector, nr_sectors, 0); |
| } |
| |
| int64_t bdrv_get_dirty_count(BlockDriverState *bs) |
| { |
| return bs->dirty_count; |
| } |
| |
| void bdrv_set_in_use(BlockDriverState *bs, int in_use) |
| { |
| assert(bs->in_use != in_use); |
| bs->in_use = in_use; |
| } |
| |
| int bdrv_in_use(BlockDriverState *bs) |
| { |
| return bs->in_use; |
| } |
| |
| void bdrv_iostatus_enable(BlockDriverState *bs) |
| { |
| bs->iostatus_enabled = true; |
| bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
| } |
| |
| /* The I/O status is only enabled if the drive explicitly |
| * enables it _and_ the VM is configured to stop on errors */ |
| bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) |
| { |
| return (bs->iostatus_enabled && |
| (bs->on_write_error == BLOCK_ERR_STOP_ENOSPC || |
| bs->on_write_error == BLOCK_ERR_STOP_ANY || |
| bs->on_read_error == BLOCK_ERR_STOP_ANY)); |
| } |
| |
| void bdrv_iostatus_disable(BlockDriverState *bs) |
| { |
| bs->iostatus_enabled = false; |
| } |
| |
| void bdrv_iostatus_reset(BlockDriverState *bs) |
| { |
| if (bdrv_iostatus_is_enabled(bs)) { |
| bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
| } |
| } |
| |
| /* XXX: Today this is set by device models because it makes the implementation |
| quite simple. However, the block layer knows about the error, so it's |
| possible to implement this without device models being involved */ |
| void bdrv_iostatus_set_err(BlockDriverState *bs, int error) |
| { |
| if (bdrv_iostatus_is_enabled(bs) && |
| bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { |
| assert(error >= 0); |
| bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : |
| BLOCK_DEVICE_IO_STATUS_FAILED; |
| } |
| } |
| |
| void |
| bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, |
| enum BlockAcctType type) |
| { |
| assert(type < BDRV_MAX_IOTYPE); |
| |
| cookie->bytes = bytes; |
| cookie->start_time_ns = get_clock(); |
| cookie->type = type; |
| } |
| |
| void |
| bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie) |
| { |
| assert(cookie->type < BDRV_MAX_IOTYPE); |
| |
| bs->nr_bytes[cookie->type] += cookie->bytes; |
| bs->nr_ops[cookie->type]++; |
| bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns; |
| } |
| |
| int bdrv_img_create(const char *filename, const char *fmt, |
| const char *base_filename, const char *base_fmt, |
| char *options, uint64_t img_size, int flags) |
| { |
| QEMUOptionParameter *param = NULL, *create_options = NULL; |
| QEMUOptionParameter *backing_fmt, *backing_file, *size; |
| BlockDriverState *bs = NULL; |
| BlockDriver *drv, *proto_drv; |
| BlockDriver *backing_drv = NULL; |
| int ret = 0; |
| |
| /* Find driver and parse its options */ |
| drv = bdrv_find_format(fmt); |
| if (!drv) { |
| error_report("Unknown file format '%s'", fmt); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| proto_drv = bdrv_find_protocol(filename); |
| if (!proto_drv) { |
| error_report("Unknown protocol '%s'", filename); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| create_options = append_option_parameters(create_options, |
| drv->create_options); |
| create_options = append_option_parameters(create_options, |
| proto_drv->create_options); |
| |
| /* Create parameter list with default values */ |
| param = parse_option_parameters("", create_options, param); |
| |
| set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size); |
| |
| /* Parse -o options */ |
| if (options) { |
| param = parse_option_parameters(options, create_options, param); |
| if (param == NULL) { |
| error_report("Invalid options for file format '%s'.", fmt); |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| if (base_filename) { |
| if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE, |
| base_filename)) { |
| error_report("Backing file not supported for file format '%s'", |
| fmt); |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| if (base_fmt) { |
| if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) { |
| error_report("Backing file format not supported for file " |
| "format '%s'", fmt); |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE); |
| if (backing_file && backing_file->value.s) { |
| if (!strcmp(filename, backing_file->value.s)) { |
| error_report("Error: Trying to create an image with the " |
| "same filename as the backing file"); |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT); |
| if (backing_fmt && backing_fmt->value.s) { |
| backing_drv = bdrv_find_format(backing_fmt->value.s); |
| if (!backing_drv) { |
| error_report("Unknown backing file format '%s'", |
| backing_fmt->value.s); |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| // The size for the image must always be specified, with one exception: |
| // If we are using a backing file, we can obtain the size from there |
| size = get_option_parameter(param, BLOCK_OPT_SIZE); |
| if (size && size->value.n == -1) { |
| if (backing_file && backing_file->value.s) { |
| uint64_t size; |
| char buf[32]; |
| int back_flags; |
| |
| /* backing files always opened read-only */ |
| back_flags = |
| flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
| |
| bs = bdrv_new(""); |
| |
| ret = bdrv_open(bs, backing_file->value.s, back_flags, backing_drv); |
| if (ret < 0) { |
| error_report("Could not open '%s'", backing_file->value.s); |
| goto out; |
| } |
| bdrv_get_geometry(bs, &size); |
| size *= 512; |
| |
| snprintf(buf, sizeof(buf), "%" PRId64, size); |
| set_option_parameter(param, BLOCK_OPT_SIZE, buf); |
| } else { |
| error_report("Image creation needs a size parameter"); |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| printf("Formatting '%s', fmt=%s ", filename, fmt); |
| print_option_parameters(param); |
| puts(""); |
| |
| ret = bdrv_create(drv, filename, param); |
| |
| if (ret < 0) { |
| if (ret == -ENOTSUP) { |
| error_report("Formatting or formatting option not supported for " |
| "file format '%s'", fmt); |
| } else if (ret == -EFBIG) { |
| error_report("The image size is too large for file format '%s'", |
| fmt); |
| } else { |
| error_report("%s: error while creating %s: %s", filename, fmt, |
| strerror(-ret)); |
| } |
| } |
| |
| out: |
| free_option_parameters(create_options); |
| free_option_parameters(param); |
| |
| if (bs) { |
| bdrv_delete(bs); |
| } |
| |
| return ret; |
| } |
| |
| void *block_job_create(const BlockJobType *job_type, BlockDriverState *bs, |
| int64_t speed, BlockDriverCompletionFunc *cb, |
| void *opaque, Error **errp) |
| { |
| BlockJob *job; |
| |
| if (bs->job || bdrv_in_use(bs)) { |
| error_set(errp, QERR_DEVICE_IN_USE, bdrv_get_device_name(bs)); |
| return NULL; |
| } |
| bdrv_set_in_use(bs, 1); |
| |
| job = g_malloc0(job_type->instance_size); |
| job->job_type = job_type; |
| job->bs = bs; |
| job->cb = cb; |
| job->opaque = opaque; |
| job->busy = true; |
| bs->job = job; |
| |
| /* Only set speed when necessary to avoid NotSupported error */ |
| if (speed != 0) { |
| Error *local_err = NULL; |
| |
| block_job_set_speed(job, speed, &local_err); |
| if (error_is_set(&local_err)) { |
| bs->job = NULL; |
| g_free(job); |
| bdrv_set_in_use(bs, 0); |
| error_propagate(errp, local_err); |
| return NULL; |
| } |
| } |
| return job; |
| } |
| |
| void block_job_complete(BlockJob *job, int ret) |
| { |
| BlockDriverState *bs = job->bs; |
| |
| assert(bs->job == job); |
| job->cb(job->opaque, ret); |
| bs->job = NULL; |
| g_free(job); |
| bdrv_set_in_use(bs, 0); |
| } |
| |
| void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) |
| { |
| Error *local_err = NULL; |
| |
| if (!job->job_type->set_speed) { |
| error_set(errp, QERR_NOT_SUPPORTED); |
| return; |
| } |
| job->job_type->set_speed(job, speed, &local_err); |
| if (error_is_set(&local_err)) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| |
| job->speed = speed; |
| } |
| |
| void block_job_cancel(BlockJob *job) |
| { |
| job->cancelled = true; |
| if (job->co && !job->busy) { |
| qemu_coroutine_enter(job->co, NULL); |
| } |
| } |
| |
| bool block_job_is_cancelled(BlockJob *job) |
| { |
| return job->cancelled; |
| } |
| |
| struct BlockCancelData { |
| BlockJob *job; |
| BlockDriverCompletionFunc *cb; |
| void *opaque; |
| bool cancelled; |
| int ret; |
| }; |
| |
| static void block_job_cancel_cb(void *opaque, int ret) |
| { |
| struct BlockCancelData *data = opaque; |
| |
| data->cancelled = block_job_is_cancelled(data->job); |
| data->ret = ret; |
| data->cb(data->opaque, ret); |
| } |
| |
| int block_job_cancel_sync(BlockJob *job) |
| { |
| struct BlockCancelData data; |
| BlockDriverState *bs = job->bs; |
| |
| assert(bs->job == job); |
| |
| /* Set up our own callback to store the result and chain to |
| * the original callback. |
| */ |
| data.job = job; |
| data.cb = job->cb; |
| data.opaque = job->opaque; |
| data.ret = -EINPROGRESS; |
| job->cb = block_job_cancel_cb; |
| job->opaque = &data; |
| block_job_cancel(job); |
| while (data.ret == -EINPROGRESS) { |
| qemu_aio_wait(); |
| } |
| return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret; |
| } |
| |
| void block_job_sleep_ns(BlockJob *job, QEMUClock *clock, int64_t ns) |
| { |
| /* Check cancellation *before* setting busy = false, too! */ |
| if (!block_job_is_cancelled(job)) { |
| job->busy = false; |
| co_sleep_ns(clock, ns); |
| job->busy = true; |
| } |
| } |