diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 343 |
1 files changed, 221 insertions, 122 deletions
@@ -649,12 +649,13 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename, 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 = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); + open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); /* * Snapshots should be writable. @@ -970,98 +971,130 @@ static void bdrv_rebind(BlockDriverState *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; + + /* geometry */ + bs_dest->cyls = bs_src->cyls; + bs_dest->heads = bs_src->heads; + bs_dest->secs = bs_src->secs; + bs_dest->translation = bs_src->translation; + + /* 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; +} + /* - * Add new bs contents at the top of an image chain while the chain is - * live, while keeping required fields on the top layer. + * 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_top. Both bs_new and bs_top are modified. + * 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_append(BlockDriverState *bs_new, BlockDriverState *bs_top) +void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) { BlockDriverState tmp; - /* bs_new must be anonymous */ + /* 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 need to stay on the top layer: */ - tmp.open_flags = bs_top->open_flags; + /* 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); - /* dev info */ - tmp.dev_ops = bs_top->dev_ops; - tmp.dev_opaque = bs_top->dev_opaque; - tmp.dev = bs_top->dev; - tmp.buffer_alignment = bs_top->buffer_alignment; - tmp.copy_on_read = bs_top->copy_on_read; - - /* i/o timing parameters */ - tmp.slice_time = bs_top->slice_time; - tmp.slice_start = bs_top->slice_start; - tmp.slice_end = bs_top->slice_end; - tmp.io_limits = bs_top->io_limits; - tmp.io_base = bs_top->io_base; - tmp.throttled_reqs = bs_top->throttled_reqs; - tmp.block_timer = bs_top->block_timer; - tmp.io_limits_enabled = bs_top->io_limits_enabled; - - /* geometry */ - tmp.cyls = bs_top->cyls; - tmp.heads = bs_top->heads; - tmp.secs = bs_top->secs; - tmp.translation = bs_top->translation; + /* bs_new shouldn't be in bdrv_states even after the swap! */ + assert(bs_new->device_name[0] == '\0'); - /* r/w error */ - tmp.on_read_error = bs_top->on_read_error; - tmp.on_write_error = bs_top->on_write_error; + /* 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); - /* i/o status */ - tmp.iostatus_enabled = bs_top->iostatus_enabled; - tmp.iostatus = bs_top->iostatus; + bdrv_rebind(bs_new); + bdrv_rebind(bs_old); +} - /* keep the same entry in bdrv_states */ - pstrcpy(tmp.device_name, sizeof(tmp.device_name), bs_top->device_name); - tmp.list = bs_top->list; +/* + * 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. */ - tmp.backing_hd = bs_new; - pstrcpy(tmp.backing_file, sizeof(tmp.backing_file), bs_top->filename); - bdrv_get_format(bs_top, tmp.backing_format, sizeof(tmp.backing_format)); - - /* swap contents of the fixed new bs and the current top */ - *bs_new = *bs_top; - *bs_top = tmp; - - /* device_name[] was carried over from the old bs_top. bs_new - * shouldn't be in bdrv_states, so we need to make device_name[] - * reflect the anonymity of bs_new - */ - bs_new->device_name[0] = '\0'; - - /* clear the copied fields in the new backing file */ - bdrv_detach_dev(bs_new, bs_new->dev); - - qemu_co_queue_init(&bs_new->throttled_reqs); - memset(&bs_new->io_base, 0, sizeof(bs_new->io_base)); - memset(&bs_new->io_limits, 0, sizeof(bs_new->io_limits)); - bdrv_iostatus_disable(bs_new); - - /* we don't use bdrv_io_limits_disable() for this, because we don't want - * to affect or delete the block_timer, as it has been moved to bs_top */ - bs_new->io_limits_enabled = false; - bs_new->block_timer = NULL; - bs_new->slice_time = 0; - bs_new->slice_start = 0; - bs_new->slice_end = 0; - - bdrv_rebind(bs_new); - bdrv_rebind(bs_top); + 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) @@ -1222,14 +1255,14 @@ bool bdrv_dev_is_medium_locked(BlockDriverState *bs) * 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) +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); + return bs->drv->bdrv_check(bs, res, fix); } #define COMMIT_BUF_SECTORS 2048 @@ -1606,6 +1639,20 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num, 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, @@ -1758,8 +1805,8 @@ int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, return ret; } - /* No flush needed for cache modes that use O_DSYNC */ - if ((bs->open_flags & BDRV_O_CACHE_WB) != 0) { + /* No flush needed for cache modes that already do it */ + if (bs->enable_write_cache) { bdrv_flush(bs); } @@ -1808,6 +1855,9 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, 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); } @@ -1977,6 +2027,10 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, 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); } @@ -2096,11 +2150,10 @@ static int guess_disk_lchs(BlockDriverState *bs, int *pcylinders, int *pheads, int *psectors) { uint8_t buf[BDRV_SECTOR_SIZE]; - int ret, i, heads, sectors, cylinders; + int i, heads, sectors, cylinders; struct partition *p; uint32_t nr_sects; uint64_t nb_sectors; - bool enabled; bdrv_get_geometry(bs, &nb_sectors); @@ -2109,12 +2162,9 @@ static int guess_disk_lchs(BlockDriverState *bs, * but also in async I/O mode. So the I/O throttling function has to * be disabled temporarily here, not permanently. */ - enabled = bs->io_limits_enabled; - bs->io_limits_enabled = false; - ret = bdrv_read(bs, 0, buf, 1); - bs->io_limits_enabled = enabled; - if (ret < 0) + if (bdrv_read_unthrottled(bs, 0, buf, 1) < 0) { return -1; + } /* test msdos magic */ if (buf[510] != 0x55 || buf[511] != 0xaa) return -1; @@ -2297,46 +2347,40 @@ void bdrv_get_floppy_geometry_hint(BlockDriverState *bs, int *nb_heads, uint64_t nb_sectors, size; int i, first_match, match; - bdrv_get_geometry_hint(bs, nb_heads, max_track, last_sect); - if (*nb_heads != 0 && *max_track != 0 && *last_sect != 0) { - /* User defined disk */ - *rate = FDRIVE_RATE_500K; - } else { - bdrv_get_geometry(bs, &nb_sectors); - match = -1; - first_match = -1; - for (i = 0; ; i++) { - parse = &fd_formats[i]; - if (parse->drive == FDRIVE_DRV_NONE) { + bdrv_get_geometry(bs, &nb_sectors); + match = -1; + first_match = -1; + for (i = 0; ; i++) { + parse = &fd_formats[i]; + if (parse->drive == FDRIVE_DRV_NONE) { + break; + } + if (drive_in == parse->drive || + drive_in == FDRIVE_DRV_NONE) { + size = (parse->max_head + 1) * parse->max_track * + parse->last_sect; + if (nb_sectors == size) { + match = i; break; } - if (drive_in == parse->drive || - drive_in == FDRIVE_DRV_NONE) { - size = (parse->max_head + 1) * parse->max_track * - parse->last_sect; - if (nb_sectors == size) { - match = i; - break; - } - if (first_match == -1) { - first_match = i; - } - } - } - if (match == -1) { if (first_match == -1) { - match = 1; - } else { - match = first_match; + first_match = i; } - parse = &fd_formats[match]; } - *nb_heads = parse->max_head + 1; - *max_track = parse->max_track; - *last_sect = parse->last_sect; - *drive = parse->drive; - *rate = parse->rate; } + if (match == -1) { + if (first_match == -1) { + match = 1; + } else { + match = first_match; + } + parse = &fd_formats[match]; + } + *nb_heads = parse->max_head + 1; + *max_track = parse->max_track; + *last_sect = parse->last_sect; + *drive = parse->drive; + *rate = parse->rate; } int bdrv_get_translation_hint(BlockDriverState *bs) @@ -2371,6 +2415,11 @@ 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) @@ -2413,13 +2462,9 @@ int bdrv_set_key(BlockDriverState *bs, const char *key) return ret; } -void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size) +const char *bdrv_get_format_name(BlockDriverState *bs) { - if (!bs->drv) { - buf[0] = '\0'; - } else { - pstrcpy(buf, buf_size, bs->drv->format_name); - } + return bs->drv ? bs->drv->format_name : NULL; } void bdrv_iterate_format(void (*it)(void *opaque, const char *name), @@ -2466,6 +2511,11 @@ 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; @@ -2569,6 +2619,55 @@ int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 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; |