This introduces a qemu-img create option for sheepdog which allows the data to be preallocated (note that sheepdog always preallocates metadata). This is necessary to use Sheepdog volumes as a backend storage for iSCSI target. More information is available at https://sourceforge.net/apps/trac/sheepdog/wiki/General%20Protocol%20Support
The option is disabled by default and you need to enable it like the following: qemu-img create sheepdog:test -o preallocation=data 1G Signed-off-by: MORITA Kazutaka <morita.kazut...@lab.ntt.co.jp> Signed-off-by: FUJITA Tomonori <fujita.tomon...@lab.ntt.co.jp> --- block/sheepdog.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 72 insertions(+), 1 deletions(-) diff --git a/block/sheepdog.c b/block/sheepdog.c index 0392ca8..38ca9aa 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -1292,6 +1292,57 @@ static int do_sd_create(char *filename, int64_t vdi_size, return 0; } +static int sd_prealloc(uint32_t vid, int64_t vdi_size) +{ + int fd, ret; + SheepdogInode *inode; + char *buf; + unsigned long idx, max_idx; + + fd = connect_to_sdog(NULL, NULL); + if (fd < 0) { + return -EIO; + } + + inode = qemu_malloc(sizeof(*inode)); + buf = qemu_malloc(SD_DATA_OBJ_SIZE); + + ret = read_object(fd, (char *)inode, vid_to_vdi_oid(vid), + 0, sizeof(*inode), 0); + + max_idx = (vdi_size + SD_DATA_OBJ_SIZE - 1) / SD_DATA_OBJ_SIZE; + + for (idx = 0; idx < max_idx; idx++) { + uint64_t oid; + oid = vid_to_data_oid(vid, idx); + + if (inode->data_vdi_id[idx]) { + ret = read_object(fd, buf, vid_to_vdi_oid(inode->data_vdi_id[idx]), + 1, SD_DATA_OBJ_SIZE, 0); + if (ret) + goto out; + } else { + memset(buf, 0, SD_DATA_OBJ_SIZE); + } + + ret = write_object(fd, buf, oid, 1, SD_DATA_OBJ_SIZE, 0, 1); + if (ret) + goto out; + + inode->data_vdi_id[idx] = vid; + ret = write_object(fd, (char *)inode, vid_to_vdi_oid(vid), + 1, sizeof(*inode), 0, 0); + if (ret) + goto out; + } +out: + free(inode); + free(buf); + closesocket(fd); + + return ret; +} + static int sd_create(const char *filename, QEMUOptionParameter *options) { int ret; @@ -1301,6 +1352,7 @@ static int sd_create(const char *filename, QEMUOptionParameter *options) BDRVSheepdogState s; char vdi[SD_MAX_VDI_LEN], tag[SD_MAX_VDI_TAG_LEN]; uint32_t snapid; + int prealloc = 0; strstart(filename, "sheepdog:", (const char **)&filename); @@ -1317,6 +1369,16 @@ static int sd_create(const char *filename, QEMUOptionParameter *options) vdi_size = options->value.n; } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { backing_file = options->value.s; + } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { + if (!options->value.s || !strcmp(options->value.s, "off")) { + prealloc = 0; + } else if (!strcmp(options->value.s, "data")) { + prealloc = 1; + } else { + error_report("Invalid preallocation mode: '%s'\n", + options->value.s); + return -EINVAL; + } } options++; } @@ -1354,7 +1416,11 @@ static int sd_create(const char *filename, QEMUOptionParameter *options) bdrv_delete(bs); } - return do_sd_create((char *)vdi, vdi_size, base_vid, &vid, 0, s.addr, s.port); + ret = do_sd_create((char *)vdi, vdi_size, base_vid, &vid, 0, s.addr, s.port); + if (!prealloc || ret) + return ret; + + return sd_prealloc(vid, vdi_size); } static void sd_close(BlockDriverState *bs) @@ -1990,6 +2056,11 @@ static QEMUOptionParameter sd_create_options[] = { .type = OPT_STRING, .help = "File name of a base image" }, + { + .name = BLOCK_OPT_PREALLOC, + .type = OPT_STRING, + .help = "Preallocation mode (allowed values: off, data)" + }, { NULL } }; -- 1.5.6.5