diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/iscsi.c | 319 |
1 files changed, 212 insertions, 107 deletions
diff --git a/block/iscsi.c b/block/iscsi.c index 52355b8bce..d649424e5c 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -30,6 +30,8 @@ #include "qemu-common.h" #include "qemu/config-file.h" #include "qemu/error-report.h" +#include "qemu/bitops.h" +#include "qemu/bitmap.h" #include "block/block_int.h" #include "trace.h" #include "block/scsi.h" @@ -59,6 +61,8 @@ typedef struct IscsiLun { struct scsi_inquiry_logical_block_provisioning lbp; struct scsi_inquiry_block_limits bl; unsigned char *zeroblock; + unsigned long *allocationmap; + int cluster_sectors; } IscsiLun; typedef struct IscsiTask { @@ -92,6 +96,15 @@ typedef struct IscsiAIOCB { #define MAX_NOP_FAILURES 3 #define ISCSI_CMD_RETRIES 5 +/* this threshhold is a trade-off knob to choose between + * the potential additional overhead of an extra GET_LBA_STATUS request + * vs. unnecessarily reading a lot of zero sectors over the wire. + * If a read request is greater or equal than ISCSI_CHECKALLOC_THRES + * sectors we check the allocation status of the area covered by the + * request first if the allocationmap indicates that the area might be + * unallocated. */ +#define ISCSI_CHECKALLOC_THRES 64 + static void iscsi_bh_cb(void *p) { @@ -273,6 +286,32 @@ static bool is_request_lun_aligned(int64_t sector_num, int nb_sectors, return 1; } +static void iscsi_allocationmap_set(IscsiLun *iscsilun, int64_t sector_num, + int nb_sectors) +{ + if (iscsilun->allocationmap == NULL) { + return; + } + bitmap_set(iscsilun->allocationmap, + sector_num / iscsilun->cluster_sectors, + DIV_ROUND_UP(nb_sectors, iscsilun->cluster_sectors)); +} + +static void iscsi_allocationmap_clear(IscsiLun *iscsilun, int64_t sector_num, + int nb_sectors) +{ + int64_t cluster_num, nb_clusters; + if (iscsilun->allocationmap == NULL) { + return; + } + cluster_num = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors); + nb_clusters = (sector_num + nb_sectors) / iscsilun->cluster_sectors + - cluster_num; + if (nb_clusters > 0) { + bitmap_clear(iscsilun->allocationmap, cluster_num, nb_clusters); + } +} + static int coroutine_fn iscsi_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *iov) @@ -336,9 +375,127 @@ retry: return -EIO; } + iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors); + return 0; } + +static bool iscsi_allocationmap_is_allocated(IscsiLun *iscsilun, + int64_t sector_num, int nb_sectors) +{ + unsigned long size; + if (iscsilun->allocationmap == NULL) { + return true; + } + size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors); + return !(find_next_bit(iscsilun->allocationmap, size, + sector_num / iscsilun->cluster_sectors) == size); +} + + +#if defined(LIBISCSI_FEATURE_IOVECTOR) + +static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs, + int64_t sector_num, + int nb_sectors, int *pnum) +{ + IscsiLun *iscsilun = bs->opaque; + struct scsi_get_lba_status *lbas = NULL; + struct scsi_lba_status_descriptor *lbasd = NULL; + struct IscsiTask iTask; + int64_t ret; + + iscsi_co_init_iscsitask(iscsilun, &iTask); + + if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) { + ret = -EINVAL; + goto out; + } + + /* default to all sectors allocated */ + ret = BDRV_BLOCK_DATA; + ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID; + *pnum = nb_sectors; + + /* LUN does not support logical block provisioning */ + if (iscsilun->lbpme == 0) { + goto out; + } + +retry: + if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun, + sector_qemu2lun(sector_num, iscsilun), + 8 + 16, iscsi_co_generic_cb, + &iTask) == NULL) { + ret = -ENOMEM; + goto out; + } + + while (!iTask.complete) { + iscsi_set_events(iscsilun); + qemu_coroutine_yield(); + } + + if (iTask.do_retry) { + if (iTask.task != NULL) { + scsi_free_scsi_task(iTask.task); + iTask.task = NULL; + } + iTask.complete = 0; + goto retry; + } + + if (iTask.status != SCSI_STATUS_GOOD) { + /* in case the get_lba_status_callout fails (i.e. + * because the device is busy or the cmd is not + * supported) we pretend all blocks are allocated + * for backwards compatibility */ + goto out; + } + + lbas = scsi_datain_unmarshall(iTask.task); + if (lbas == NULL) { + ret = -EIO; + goto out; + } + + lbasd = &lbas->descriptors[0]; + + if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) { + ret = -EIO; + goto out; + } + + *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun); + + if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED || + lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) { + ret &= ~BDRV_BLOCK_DATA; + if (iscsilun->lbprz) { + ret |= BDRV_BLOCK_ZERO; + } + } + + if (ret & BDRV_BLOCK_ZERO) { + iscsi_allocationmap_clear(iscsilun, sector_num, *pnum); + } else { + iscsi_allocationmap_set(iscsilun, sector_num, *pnum); + } + + if (*pnum > nb_sectors) { + *pnum = nb_sectors; + } +out: + if (iTask.task != NULL) { + scsi_free_scsi_task(iTask.task); + } + return ret; +} + +#endif /* LIBISCSI_FEATURE_IOVECTOR */ + + static int coroutine_fn iscsi_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *iov) @@ -355,6 +512,22 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs, return -EINVAL; } +#if defined(LIBISCSI_FEATURE_IOVECTOR) + if (iscsilun->lbprz && nb_sectors >= ISCSI_CHECKALLOC_THRES && + !iscsi_allocationmap_is_allocated(iscsilun, sector_num, nb_sectors)) { + int64_t ret; + int pnum; + ret = iscsi_co_get_block_status(bs, sector_num, INT_MAX, &pnum); + if (ret < 0) { + return ret; + } + if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors) { + qemu_iovec_memset(iov, 0, 0x00, iov->size); + return 0; + } + } +#endif + lba = sector_qemu2lun(sector_num, iscsilun); num_sectors = sector_qemu2lun(nb_sectors, iscsilun); @@ -643,101 +816,6 @@ iscsi_getlength(BlockDriverState *bs) return len; } -#if defined(LIBISCSI_FEATURE_IOVECTOR) - -static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs, - int64_t sector_num, - int nb_sectors, int *pnum) -{ - IscsiLun *iscsilun = bs->opaque; - struct scsi_get_lba_status *lbas = NULL; - struct scsi_lba_status_descriptor *lbasd = NULL; - struct IscsiTask iTask; - int64_t ret; - - iscsi_co_init_iscsitask(iscsilun, &iTask); - - if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) { - ret = -EINVAL; - goto out; - } - - /* default to all sectors allocated */ - ret = BDRV_BLOCK_DATA; - ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID; - *pnum = nb_sectors; - - /* LUN does not support logical block provisioning */ - if (iscsilun->lbpme == 0) { - goto out; - } - -retry: - if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun, - sector_qemu2lun(sector_num, iscsilun), - 8 + 16, iscsi_co_generic_cb, - &iTask) == NULL) { - ret = -ENOMEM; - goto out; - } - - while (!iTask.complete) { - iscsi_set_events(iscsilun); - qemu_coroutine_yield(); - } - - if (iTask.do_retry) { - if (iTask.task != NULL) { - scsi_free_scsi_task(iTask.task); - iTask.task = NULL; - } - iTask.complete = 0; - goto retry; - } - - if (iTask.status != SCSI_STATUS_GOOD) { - /* in case the get_lba_status_callout fails (i.e. - * because the device is busy or the cmd is not - * supported) we pretend all blocks are allocated - * for backwards compatibility */ - goto out; - } - - lbas = scsi_datain_unmarshall(iTask.task); - if (lbas == NULL) { - ret = -EIO; - goto out; - } - - lbasd = &lbas->descriptors[0]; - - if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) { - ret = -EIO; - goto out; - } - - *pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun); - if (*pnum > nb_sectors) { - *pnum = nb_sectors; - } - - if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED || - lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) { - ret &= ~BDRV_BLOCK_DATA; - if (iscsilun->lbprz) { - ret |= BDRV_BLOCK_ZERO; - } - } - -out: - if (iTask.task != NULL) { - scsi_free_scsi_task(iTask.task); - } - return ret; -} - -#endif /* LIBISCSI_FEATURE_IOVECTOR */ - static int coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) @@ -791,6 +869,8 @@ retry: return -EIO; } + iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors); + return 0; } @@ -809,13 +889,14 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num, return -EINVAL; } - if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) { - /* WRITE SAME without UNMAP is not supported by the target */ - return -ENOTSUP; + if ((flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->lbp.lbpws) { + /* WRITE SAME with UNMAP is not supported by the target, + * fall back and try WRITE SAME without UNMAP */ + flags &= ~BDRV_REQ_MAY_UNMAP; } - if ((flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->lbp.lbpws) { - /* WRITE SAME with UNMAP is not supported by the target */ + if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) { + /* WRITE SAME without UNMAP is not supported by the target */ return -ENOTSUP; } @@ -864,6 +945,12 @@ retry: return -EIO; } + if (flags & BDRV_REQ_MAY_UNMAP) { + iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors); + } else { + iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors); + } + return 0; } @@ -1295,6 +1382,22 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags, timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL); #endif + /* Guess the internal cluster (page) size of the iscsi target by the means + * of opt_unmap_gran. Transfer the unmap granularity only if it has a + * reasonable size */ + if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 && + iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) { + iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran * + iscsilun->block_size) >> BDRV_SECTOR_BITS; +#if defined(LIBISCSI_FEATURE_IOVECTOR) + if (iscsilun->lbprz && !(bs->open_flags & BDRV_O_NOCACHE)) { + iscsilun->allocationmap = + bitmap_new(DIV_ROUND_UP(bs->total_sectors, + iscsilun->cluster_sectors)); + } +#endif + } + out: qemu_opts_del(opts); if (initiator_name != NULL) { @@ -1328,6 +1431,7 @@ static void iscsi_close(BlockDriverState *bs) qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), NULL, NULL, NULL); iscsi_destroy_context(iscsi); g_free(iscsilun->zeroblock); + g_free(iscsilun->allocationmap); memset(iscsilun, 0, sizeof(IscsiLun)); } @@ -1388,6 +1492,13 @@ static int iscsi_truncate(BlockDriverState *bs, int64_t offset) return -EINVAL; } + if (iscsilun->allocationmap != NULL) { + g_free(iscsilun->allocationmap); + iscsilun->allocationmap = + bitmap_new(DIV_ROUND_UP(bs->total_sectors, + iscsilun->cluster_sectors)); + } + return 0; } @@ -1450,13 +1561,7 @@ static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) IscsiLun *iscsilun = bs->opaque; bdi->unallocated_blocks_are_zero = !!iscsilun->lbprz; bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws; - /* Guess the internal cluster (page) size of the iscsi target by the means - * of opt_unmap_gran. Transfer the unmap granularity only if it has a - * reasonable size for bdi->cluster_size */ - if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 64 * 1024 && - iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) { - bdi->cluster_size = iscsilun->bl.opt_unmap_gran * iscsilun->block_size; - } + bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE; return 0; } |