/* * 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 "monitor.h" #include "block_int.h" #include "module.h" #include "qemu-objects.h" #ifdef CONFIG_BSD #include #include #include #include #ifndef __DragonFly__ #include #endif #endif #ifdef _WIN32 #include #endif 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 BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque); static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors); static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors); static BlockDriver *find_protocol(const char *filename); static QTAILQ_HEAD(, BlockDriverState) bdrv_states = QTAILQ_HEAD_INITIALIZER(bdrv_states); static QLIST_HEAD(, BlockDriver) bdrv_drivers = QLIST_HEAD_INITIALIZER(bdrv_drivers); /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; int path_is_absolute(const char *path) { const char *p; #ifdef _WIN32 /* specific case for names like: "\\.\d:" */ if (*path == '/' || *path == '\\') return 1; #endif p = strchr(path, ':'); if (p) p++; else p = path; #ifdef _WIN32 return (*p == '/' || *p == '\\'); #else return (*p == '/'); #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_register(BlockDriver *bdrv) { 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; } else if (!bdrv->bdrv_read) { /* add synchronous IO emulation layer */ bdrv->bdrv_read = bdrv_read_em; bdrv->bdrv_write = bdrv_write_em; } if (!bdrv->bdrv_aio_flush) bdrv->bdrv_aio_flush = bdrv_aio_flush_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 = qemu_mallocz(sizeof(BlockDriverState)); pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); if (device_name[0] != '\0') { QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); } 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; } int bdrv_create(BlockDriver *drv, const char* filename, QEMUOptionParameter *options) { if (!drv->bdrv_create) return -ENOTSUP; return drv->bdrv_create(filename, options); } int bdrv_create_file(const char* filename, QEMUOptionParameter *options) { BlockDriver *drv; drv = find_protocol(filename); if (drv == NULL) { drv = bdrv_find_format("file"); } return bdrv_create(drv, filename, options); } #ifdef _WIN32 void get_tmp_filename(char *filename, int size) { char temp_dir[MAX_PATH]; GetTempPath(MAX_PATH, temp_dir); GetTempFileName(temp_dir, "qem", 0, filename); } #else void get_tmp_filename(char *filename, int size) { int fd; const char *tmpdir; /* XXX: race condition possible */ tmpdir = getenv("TMPDIR"); if (!tmpdir) tmpdir = "/tmp"; snprintf(filename, size, "%s/vl.XXXXXX", tmpdir); fd = mkstemp(filename); close(fd); } #endif #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 /* * 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; } static BlockDriver *find_protocol(const char *filename) { BlockDriver *drv1; char protocol[128]; int len; const char *p; int is_drive; /* TODO Drivers without bdrv_file_open must be specified explicitly */ #ifdef _WIN32 is_drive = is_windows_drive(filename) || is_windows_drive_prefix(filename); #else is_drive = 0; #endif p = strchr(filename, ':'); if (!p || is_drive) { drv1 = find_hdev_driver(filename); if (!drv1) { drv1 = bdrv_find_format("file"); } return drv1; } 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 BlockDriver *find_image_format(const char *filename) { int ret, score, score_max; BlockDriver *drv1, *drv; uint8_t buf[2048]; BlockDriverState *bs; ret = bdrv_file_open(&bs, filename, 0); if (ret < 0) return NULL; /* Return the raw BlockDriver * to scsi-generic devices */ if (bs->sg) return bdrv_find_format("raw"); ret = bdrv_pread(bs, 0, buf, sizeof(buf)); bdrv_delete(bs); if (ret < 0) { return NULL; } 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; } } } return drv; } /** * 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; } /* * 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); bs->file = NULL; bs->total_sectors = 0; bs->is_temporary = 0; bs->encrypted = 0; bs->valid_key = 0; bs->open_flags = flags; /* buffer_alignment defaulted to 512, drivers can change this value */ bs->buffer_alignment = 512; pstrcpy(bs->filename, sizeof(bs->filename), filename); if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) { return -ENOTSUP; } bs->drv = drv; bs->opaque = qemu_mallocz(drv->instance_size); /* * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a * write cache to the guest. We do need the fdatasync to flush * out transactions for block allocations, and we maybe have a * volatile write cache in our backing device to deal with. */ if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE)) bs->enable_write_cache = 1; /* * Clear flags that are internal to the block layer before opening the * image. */ open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); /* * Snapshots should be writeable. */ if (bs->is_temporary) { 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; } bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR); 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; } qemu_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 = 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; if (flags & BDRV_O_SNAPSHOT) { BlockDriverState *bs1; int64_t total_size; int is_protocol = 0; BlockDriver *bdrv_qcow2; QEMUOptionParameter *options; char tmp_filename[PATH_MAX]; 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_BITS; if (bs1->drv && bs1->drv->protocol_name) is_protocol = 1; bdrv_delete(bs1); get_tmp_filename(tmp_filename, sizeof(tmp_filename)); /* 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 * 512); 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) { drv = find_image_format(filename); } if (!drv) { ret = -ENOENT; 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(""); path_combine(backing_filename, sizeof(backing_filename), filename, bs->backing_file); 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)) { /* call the change callback */ bs->media_changed = 1; if (bs->change_cb) bs->change_cb(bs->change_opaque); } return 0; unlink_and_fail: if (bs->is_temporary) { unlink(filename); } return ret; } void bdrv_close(BlockDriverState *bs) { if (bs->drv) { if (bs->backing_hd) { bdrv_delete(bs->backing_hd); bs->backing_hd = NULL; } bs->drv->bdrv_close(bs); qemu_free(bs->opaque); #ifdef _WIN32 if (bs->is_temporary) { unlink(bs->filename); } #endif bs->opaque = NULL; bs->drv = NULL; if (bs->file != NULL) { bdrv_close(bs->file); } /* call the change callback */ bs->media_changed = 1; if (bs->change_cb) bs->change_cb(bs->change_opaque); } } void bdrv_delete(BlockDriverState *bs) { /* remove from list, if necessary */ if (bs->device_name[0] != '\0') { QTAILQ_REMOVE(&bdrv_states, bs, list); } bdrv_close(bs); if (bs->file != NULL) { bdrv_delete(bs->file); } qemu_free(bs); } /* * Run consistency checks on an image * * Returns the number of errors or -errno when an internal error occurs */ int bdrv_check(BlockDriverState *bs) { if (bs->drv->bdrv_check == NULL) { return -ENOTSUP; } return bs->drv->bdrv_check(bs); } /* commit COW file into the raw image */ int bdrv_commit(BlockDriverState *bs) { BlockDriver *drv = bs->drv; int64_t i, total_sectors; int n, j, ro, open_flags; int ret = 0, rw_ret = 0; unsigned char sector[512]; 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; } 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, 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, 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; for (i = 0; i < total_sectors;) { if (drv->bdrv_is_allocated(bs, i, 65536, &n)) { for(j = 0; j < n; j++) { if (bdrv_read(bs, i, sector, 1) != 0) { ret = -EIO; goto ro_cleanup; } if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) { ret = -EIO; goto ro_cleanup; } i++; } } else { i += n; } } 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: 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, 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; } /* * 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; if (drv->bdrv_change_backing_file != NULL) { return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); } else { return -ENOTSUP; } } 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 * 512, nb_sectors * 512); } /* 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) { BlockDriver *drv = bs->drv; if (!drv) return -ENOMEDIUM; if (bdrv_check_request(bs, sector_num, nb_sectors)) return -EIO; return drv->bdrv_read(bs, sector_num, buf, nb_sectors); } 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 / (sizeof(unsigned long) * 8); bit = start % (sizeof(unsigned long) * 8); val = bs->dirty_bitmap[idx]; if (dirty) { if (!(val & (1 << bit))) { bs->dirty_count++; val |= 1 << bit; } } else { if (val & (1 << bit)) { bs->dirty_count--; val &= ~(1 << 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) { BlockDriver *drv = bs->drv; if (!bs->drv) return -ENOMEDIUM; if (bs->read_only) return -EACCES; if (bdrv_check_request(bs, sector_num, nb_sectors)) return -EIO; 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; } return drv->bdrv_write(bs, sector_num, buf, nb_sectors); } 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; } /** * 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; ret = drv->bdrv_truncate(bs, offset); if (ret == 0) { ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); } return ret; } /** * 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; /* Fixed size devices use the total_sectors value for speed instead of issuing a length query (like lseek) on each call. Also, legacy block drivers don't provide a bdrv_getlength function and must use total_sectors. */ if (!bs->growable || !drv->bdrv_getlength) { return bs->total_sectors * BDRV_SECTOR_SIZE; } return drv->bdrv_getlength(bs); } /* 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; } struct partition { uint8_t boot_ind; /* 0x80 - active */ uint8_t head; /* starting head */ uint8_t sector; /* starting sector */ uint8_t cyl; /* starting cylinder */ uint8_t sys_ind; /* What partition type */ uint8_t end_head; /* end head */ uint8_t end_sector; /* end sector */ uint8_t end_cyl; /* end cylinder */ uint32_t start_sect; /* starting sector counting from 0 */ uint32_t nr_sects; /* nr of sectors in partition */ } __attribute__((packed)); /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */ static int guess_disk_lchs(BlockDriverState *bs, int *pcylinders, int *pheads, int *psectors) { uint8_t buf[512]; int ret, i, heads, sectors, cylinders; struct partition *p; uint32_t nr_sects; uint64_t nb_sectors; bdrv_get_geometry(bs, &nb_sectors); ret = bdrv_read(bs, 0, buf, 1); if (ret < 0) return -1; /* test msdos magic */ if (buf[510] != 0x55 || buf[511] != 0xaa) return -1; for(i = 0; i < 4; i++) { p = ((struct partition *)(buf + 0x1be)) + i; nr_sects = le32_to_cpu(p->nr_sects); if (nr_sects && p->end_head) { /* We make the assumption that the partition terminates on a cylinder boundary */ heads = p->end_head + 1; sectors = p->end_sector & 63; if (sectors == 0) continue; cylinders = nb_sectors / (heads * sectors); if (cylinders < 1 || cylinders > 16383) continue; *pheads = heads; *psectors = sectors; *pcylinders = cylinders; #if 0 printf("guessed geometry: LCHS=%d %d %d\n", cylinders, heads, sectors); #endif return 0; } } return -1; } void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs) { int translation, lba_detected = 0; int cylinders, heads, secs; uint64_t nb_sectors; /* if a geometry hint is available, use it */ bdrv_get_geometry(bs, &nb_sectors); bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs); translation = bdrv_get_translation_hint(bs); if (cylinders != 0) { *pcyls = cylinders; *pheads = heads; *psecs = secs; } else { if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) { if (heads > 16) { /* if heads > 16, it means that a BIOS LBA translation was active, so the default hardware geometry is OK */ lba_detected = 1; goto default_geometry; } else { *pcyls = cylinders; *pheads = heads; *psecs = secs; /* disable any translation to be in sync with the logical geometry */ if (translation == BIOS_ATA_TRANSLATION_AUTO) { bdrv_set_translation_hint(bs, BIOS_ATA_TRANSLATION_NONE); } } } else { default_geometry: /* if no geometry, use a standard physical disk geometry */ cylinders = nb_sectors / (16 * 63); if (cylinders > 16383) cylinders = 16383; else if (cylinders < 2) cylinders = 2; *pcyls = cylinders; *pheads = 16; *psecs = 63; if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) { if ((*pcyls * *pheads) <= 131072) { bdrv_set_translation_hint(bs, BIOS_ATA_TRANSLATION_LARGE); } else { bdrv_set_translation_hint(bs, BIOS_ATA_TRANSLATION_LBA); } } } bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs); } } void bdrv_set_geometry_hint(BlockDriverState *bs, int cyls, int heads, int secs) { bs->cyls = cyls; bs->heads = heads; bs->secs = secs; } void bdrv_set_type_hint(BlockDriverState *bs, int type) { bs->type = type; bs->removable = ((type == BDRV_TYPE_CDROM || type == BDRV_TYPE_FLOPPY)); } void bdrv_set_translation_hint(BlockDriverState *bs, int translation) { bs->translation = translation; } void bdrv_get_geometry_hint(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs) { *pcyls = bs->cyls; *pheads = bs->heads; *psecs = bs->secs; } int bdrv_get_type_hint(BlockDriverState *bs) { return bs->type; } int bdrv_get_translation_hint(BlockDriverState *bs) { return bs->translation; } int bdrv_is_removable(BlockDriverState *bs) { return bs->removable; } 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; } /* XXX: no longer used */ void bdrv_set_change_cb(BlockDriverState *bs, void (*change_cb)(void *opaque), void *opaque) { bs->change_cb = change_cb; bs->change_opaque = opaque; } 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 */ bs->media_changed = 1; if (bs->change_cb) bs->change_cb(bs->change_opaque); } return ret; } void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size) { if (!bs->drv) { buf[0] = '\0'; } else { pstrcpy(buf, buf_size, bs->drv->format_name); } } 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; } 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; } void bdrv_flush(BlockDriverState *bs) { if (bs->drv && bs->drv->bdrv_flush) bs->drv->bdrv_flush(bs); } void bdrv_flush_all(void) { BlockDriverState *bs; QTAILQ_FOREACH(bs, &bdrv_states, list) { if (bs->drv && !bdrv_is_read_only(bs) && (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) { bdrv_flush(bs); } } } int bdrv_has_zero_init(BlockDriverState *bs) { assert(bs->drv); if (bs->drv->no_zero_init) { return 0; } else if (bs->file) { return bdrv_has_zero_init(bs->file); } return 1; } /* * 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. * * '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. */ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { int64_t n; if (!bs->drv->bdrv_is_allocated) { if (sector_num >= bs->total_sectors) { *pnum = 0; return 0; } n = bs->total_sectors - sector_num; *pnum = (n < nb_sectors) ? (n) : (nb_sectors); return 1; } return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum); } void bdrv_mon_event(const BlockDriverState *bdrv, BlockMonEventAction 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_print_dict(QObject *obj, void *opaque) { QDict *bs_dict; Monitor *mon = opaque; bs_dict = qobject_to_qdict(obj); monitor_printf(mon, "%s: type=%s removable=%d", qdict_get_str(bs_dict, "device"), qdict_get_str(bs_dict, "type"), qdict_get_bool(bs_dict, "removable")); if (qdict_get_bool(bs_dict, "removable")) { monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked")); } if (qdict_haskey(bs_dict, "inserted")) { QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted")); monitor_printf(mon, " file="); monitor_print_filename(mon, qdict_get_str(qdict, "file")); if (qdict_haskey(qdict, "backing_file")) { monitor_printf(mon, " backing_file="); monitor_print_filename(mon, qdict_get_str(qdict, "backing_file")); } monitor_printf(mon, " ro=%d drv=%s encrypted=%d", qdict_get_bool(qdict, "ro"), qdict_get_str(qdict, "drv"), qdict_get_bool(qdict, "encrypted")); } else { monitor_printf(mon, " [not inserted]"); } monitor_printf(mon, "\n"); } void bdrv_info_print(Monitor *mon, const QObject *data) { qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon); } /** * bdrv_info(): Block devices information * * Each block device information is stored in a QDict and the * returned QObject is a QList of all devices. * * The QDict contains the following: * * - "device": device name * - "type": device type * - "removable": true if the device is removable, false otherwise * - "locked": true if the device is locked, false otherwise * - "inserted": only present if the device is inserted, it is a QDict * containing the following: * - "file": device file name * - "ro": true if read-only, false otherwise * - "drv": driver format name * - "backing_file": backing file name if one is used * - "encrypted": true if encrypted, false otherwise * * Example: * * [ { "device": "ide0-hd0", "type": "hd", "removable": false, "locked": false, * "inserted": { "file": "/tmp/foobar", "ro": false, "drv": "qcow2" } }, * { "device": "floppy0", "type": "floppy", "removable": true, * "locked": false } ] */ void bdrv_info(Monitor *mon, QObject **ret_data) { QList *bs_list; BlockDriverState *bs; bs_list = qlist_new(); QTAILQ_FOREACH(bs, &bdrv_states, list) { QObject *bs_obj; const char *type = "unknown"; switch(bs->type) { case BDRV_TYPE_HD: type = "hd"; break; case BDRV_TYPE_CDROM: type = "cdrom"; break; case BDRV_TYPE_FLOPPY: type = "floppy"; break; } bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, " "'removable': %i, 'locked': %i }", bs->device_name, type, bs->removable, bs->locked); if (bs->drv) { QObject *obj; QDict *bs_dict = qobject_to_qdict(bs_obj); obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, " "'encrypted': %i }", bs->filename, bs->read_only, bs->drv->format_name, bdrv_is_encrypted(bs)); if (bs->backing_file[0] != '\0') { QDict *qdict = qobject_to_qdict(obj); qdict_put(qdict, "backing_file", qstring_from_str(bs->backing_file)); } qdict_put_obj(bs_dict, "inserted", obj); } qlist_append_obj(bs_list, bs_obj); } *ret_data = QOBJECT(bs_list); } static void bdrv_stats_iter(QObject *data, void *opaque) { QDict *qdict; Monitor *mon = opaque; qdict = qobject_to_qdict(data); monitor_printf(mon, "%s:", qdict_get_str(qdict, "device")); qdict = qobject_to_qdict(qdict_get(qdict, "stats")); monitor_printf(mon, " rd_bytes=%" PRId64 " wr_bytes=%" PRId64 " rd_operations=%" PRId64 " wr_operations=%" PRId64 "\n", qdict_get_int(qdict, "rd_bytes"), qdict_get_int(qdict, "wr_bytes"), qdict_get_int(qdict, "rd_operations"), qdict_get_int(qdict, "wr_operations")); } void bdrv_stats_print(Monitor *mon, const QObject *data) { qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon); } static QObject* bdrv_info_stats_bs(BlockDriverState *bs) { QObject *res; QDict *dict; res = qobject_from_jsonf("{ 'stats': {" "'rd_bytes': %" PRId64 "," "'wr_bytes': %" PRId64 "," "'rd_operations': %" PRId64 "," "'wr_operations': %" PRId64 "," "'wr_highest_offset': %" PRId64 "} }", bs->rd_bytes, bs->wr_bytes, bs->rd_ops, bs->wr_ops, bs->wr_highest_sector * 512); dict = qobject_to_qdict(res); if (*bs->device_name) { qdict_put(dict, "device", qstring_from_str(bs->device_name)); } if (bs->file) { QObject *parent = bdrv_info_stats_bs(bs->file); qdict_put_obj(dict, "parent", parent); } return res; } /** * bdrv_info_stats(): show block device statistics * * Each device statistic information is stored in a QDict and * the returned QObject is a QList of all devices. * * The QDict contains the following: * * - "device": device name * - "stats": A QDict with the statistics information, it contains: * - "rd_bytes": bytes read * - "wr_bytes": bytes written * - "rd_operations": read operations * - "wr_operations": write operations * - "wr_highest_offset": Highest offset of a sector written since the * BlockDriverState has been opened * - "parent": A QDict recursively holding the statistics of the underlying * protocol (e.g. the host file for a qcow2 image). If there is no * underlying protocol, this field is omitted. * * Example: * * [ { "device": "ide0-hd0", * "stats": { "rd_bytes": 512, * "wr_bytes": 0, * "rd_operations": 1, * "wr_operations": 0, * "wr_highest_offset": 0 }, * "parent": { * "stats": { "rd_bytes": 1024, * "wr_bytes": 0, * "rd_operations": 2, * "wr_operations": 0, * "wr_highest_offset": 0, * } } }, * { "device": "ide1-cd0", * "stats": { "rd_bytes": 0, * "wr_bytes": 0, * "rd_operations": 0, * "wr_operations": 0, * "wr_highest_offset": 0 } }, */ void bdrv_info_stats(Monitor *mon, QObject **ret_data) { QObject *obj; QList *devices; BlockDriverState *bs; devices = qlist_new(); QTAILQ_FOREACH(bs, &bdrv_states, list) { obj = bdrv_info_stats_bs(bs); qlist_append_obj(devices, obj); } *ret_data = QOBJECT(devices); } 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) { if (!bs->backing_file) { pstrcpy(filename, filename_size, ""); } else { 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 -ENOTSUP; return drv->bdrv_save_vmstate(bs, buf, pos, size); } 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 -ENOTSUP; return drv->bdrv_load_vmstate(bs, buf, pos, size); } void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event) { BlockDriver *drv = bs->drv; if (!drv || !drv->bdrv_debug_event) { return; } return drv->bdrv_debug_event(bs, event); } /**************************************************************/ /* handling of snapshots */ int bdrv_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info) { BlockDriver *drv = bs->drv; if (!drv) return -ENOMEDIUM; if (!drv->bdrv_snapshot_create) return -ENOTSUP; return drv->bdrv_snapshot_create(bs, sn_info); } int bdrv_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) { BlockDriver *drv = bs->drv; if (!drv) return -ENOMEDIUM; if (!drv->bdrv_snapshot_goto) return -ENOTSUP; return drv->bdrv_snapshot_goto(bs, snapshot_id); } int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) { BlockDriver *drv = bs->drv; if (!drv) return -ENOMEDIUM; if (!drv->bdrv_snapshot_delete) return -ENOTSUP; return drv->bdrv_snapshot_delete(bs, snapshot_id); } int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info) { BlockDriver *drv = bs->drv; if (!drv) return -ENOMEDIUM; if (!drv->bdrv_snapshot_list) return -ENOTSUP; return drv->bdrv_snapshot_list(bs, psn_info); } #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) { BlockDriver *drv = bs->drv; BlockDriverAIOCB *ret; if (!drv) return NULL; if (bdrv_check_request(bs, sector_num, nb_sectors)) return NULL; ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors, cb, opaque); if (ret) { /* Update stats even though technically transfer has not happened. */ bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE; bs->rd_ops ++; } return ret; } BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque) { BlockDriver *drv = bs->drv; BlockDriverAIOCB *ret; if (!drv) return NULL; if (bs->read_only) return NULL; if (bdrv_check_request(bs, sector_num, nb_sectors)) return NULL; if (bs->dirty_bitmap) { set_dirty_bitmap(bs, sector_num, nb_sectors, 1); } ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors, cb, opaque); if (ret) { /* Update stats even though technically transfer has not happened. */ bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE; bs->wr_ops ++; if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { bs->wr_highest_sector = sector_num + nb_sectors - 1; } } return ret; } typedef struct MultiwriteCB { int error; int num_requests; int num_callbacks; struct { BlockDriverCompletionFunc *cb; void *opaque; QEMUIOVector *free_qiov; void *free_buf; } 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); } qemu_free(mcb->callbacks[i].free_qiov); qemu_vfree(mcb->callbacks[i].free_buf); } } static void multiwrite_cb(void *opaque, int ret) { MultiwriteCB *mcb = opaque; if (ret < 0 && !mcb->error) { mcb->error = ret; multiwrite_user_cb(mcb); } mcb->num_requests--; if (mcb->num_requests == 0) { if (mcb->error == 0) { multiwrite_user_cb(mcb); } qemu_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; // This handles the cases that are valid for all block drivers, namely // exactly sequential writes and overlapping writes. if (reqs[i].sector <= oldreq_last) { merge = 1; } // The block driver may decide that it makes sense to combine requests // even if there is a gap of some sectors between them. In this case, // the gap is filled with zeros (therefore only applicable for yet // unused space in format like qcow2). if (!merge && bs->drv->bdrv_merge_requests) { merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]); } if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { merge = 0; } if (merge) { size_t size; QEMUIOVector *qiov = qemu_mallocz(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, size); // We might need to add some zeros between the two requests if (reqs[i].sector > oldreq_last) { size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9; uint8_t *buf = qemu_blockalign(bs, zero_bytes); memset(buf, 0, zero_bytes); qemu_iovec_add(qiov, buf, zero_bytes); mcb->callbacks[i].free_buf = buf; } // Add the second request qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size); reqs[outidx].nb_sectors += reqs[i].nb_sectors; 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) { BlockDriverAIOCB *acb; MultiwriteCB *mcb; int i; if (num_reqs == 0) { return 0; } // Create MultiwriteCB structure mcb = qemu_mallocz(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); // Run the aio requests for (i = 0; i < num_reqs; i++) { acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov, reqs[i].nb_sectors, multiwrite_cb, mcb); if (acb == NULL) { // We can only fail the whole thing if no request has been // submitted yet. Otherwise we'll wait for the submitted AIOs to // complete and report the error in the callback. if (mcb->num_requests == 0) { reqs[i].error = -EIO; goto fail; } else { mcb->num_requests++; multiwrite_cb(mcb, -EIO); break; } } else { mcb->num_requests++; } } return 0; fail: qemu_free(mcb); return -1; } BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque) { BlockDriver *drv = bs->drv; if (!drv) return NULL; return drv->bdrv_aio_flush(bs, cb, opaque); } void bdrv_aio_cancel(BlockDriverAIOCB *acb) { acb->pool->cancel(acb); } /**************************************************************/ /* 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_buffer(acb->qiov, 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); if (!acb->bh) acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); if (is_write) { qemu_iovec_to_buffer(acb->qiov, acb->bounce); acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors); } else { acb->ret = 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); } static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque) { BlockDriverAIOCBSync *acb; acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque); acb->is_write = 1; /* don't bounce in the completion hadler */ acb->qiov = NULL; acb->bounce = NULL; acb->ret = 0; if (!acb->bh) acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); bdrv_flush(bs); qemu_bh_schedule(acb->bh); return &acb->common; } /**************************************************************/ /* sync block device emulation */ static void bdrv_rw_em_cb(void *opaque, int ret) { *(int *)opaque = ret; } #define NOT_DONE 0x7fffffff static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { int async_ret; BlockDriverAIOCB *acb; struct iovec iov; QEMUIOVector qiov; async_context_push(); async_ret = NOT_DONE; iov.iov_base = (void *)buf; iov.iov_len = nb_sectors * 512; qemu_iovec_init_external(&qiov, &iov, 1); acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors, bdrv_rw_em_cb, &async_ret); if (acb == NULL) { async_ret = -1; goto fail; } while (async_ret == NOT_DONE) { qemu_aio_wait(); } fail: async_context_pop(); return async_ret; } static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { int async_ret; BlockDriverAIOCB *acb; struct iovec iov; QEMUIOVector qiov; async_context_push(); async_ret = NOT_DONE; iov.iov_base = (void *)buf; iov.iov_len = nb_sectors * 512; qemu_iovec_init_external(&qiov, &iov, 1); acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors, bdrv_rw_em_cb, &async_ret); if (acb == NULL) { async_ret = -1; goto fail; } while (async_ret == NOT_DONE) { qemu_aio_wait(); } fail: async_context_pop(); return async_ret; } 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 = qemu_mallocz(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; } /**************************************************************/ /* removable device support */ /** * Return TRUE if the media is present */ int bdrv_is_inserted(BlockDriverState *bs) { BlockDriver *drv = bs->drv; int ret; if (!drv) return 0; if (!drv->bdrv_is_inserted) return 1; ret = drv->bdrv_is_inserted(bs); return ret; } /** * Return TRUE if the media changed since the last call to this * function. It is currently only used for floppy disks */ int bdrv_media_changed(BlockDriverState *bs) { BlockDriver *drv = bs->drv; int ret; if (!drv || !drv->bdrv_media_changed) ret = -ENOTSUP; else ret = drv->bdrv_media_changed(bs); if (ret == -ENOTSUP) ret = bs->media_changed; bs->media_changed = 0; return ret; } /** * If eject_flag is TRUE, eject the media. Otherwise, close the tray */ int bdrv_eject(BlockDriverState *bs, int eject_flag) { BlockDriver *drv = bs->drv; int ret; if (bs->locked) { return -EBUSY; } if (!drv || !drv->bdrv_eject) { ret = -ENOTSUP; } else { ret = drv->bdrv_eject(bs, eject_flag); } if (ret == -ENOTSUP) { if (eject_flag) bdrv_close(bs); ret = 0; } return ret; } int bdrv_is_locked(BlockDriverState *bs) { return bs->locked; } /** * Lock or unlock the media (if it is locked, the user won't be able * to eject it manually). */ void bdrv_set_locked(BlockDriverState *bs, int locked) { BlockDriver *drv = bs->drv; bs->locked = locked; if (drv && drv->bdrv_set_locked) { drv->bdrv_set_locked(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 *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 * 8 - 1; bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8; bs->dirty_bitmap = qemu_mallocz(bitmap_size); } } else { if (bs->dirty_bitmap) { qemu_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)] & (1 << (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; }