* QEMU Block driver for iSCSI images
*
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
#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"
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 {
#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)
{
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)
return -EIO;
}
+ iscsi_allocationmap_set(iscsilun, sector_num, nb_sectors);
+
return 0;
}
+
+#if defined(LIBISCSI_FEATURE_IOVECTOR)
+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);
+}
+
+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)
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);
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)
return -EIO;
}
+ iscsi_allocationmap_clear(iscsilun, sector_num, nb_sectors);
+
return 0;
}
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;
}
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;
}
*inq = scsi_datain_unmarshall(task);
if (*inq == NULL) {
error_setg(errp, "iSCSI: failed to unmarshall inquiry datain blob");
- goto fail;
+ goto fail_with_err;
}
return task;
fail:
- if (!error_is_set(errp)) {
- error_setg(errp, "iSCSI: Inquiry command failed : %s",
- iscsi_get_error(iscsi));
- }
+ error_setg(errp, "iSCSI: Inquiry command failed : %s",
+ iscsi_get_error(iscsi));
+fail_with_err:
if (task != NULL) {
scsi_free_scsi_task(task);
}
iscsi_readcapacity_sync(iscsilun, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
+ ret = -EINVAL;
goto out;
}
bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
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) {
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));
}
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;
}
IscsiLun *iscsilun = NULL;
QDict *bs_options;
- bs = bdrv_new("");
+ bs = bdrv_new("", &error_abort);
/* Read out options */
while (options && options->name) {
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;
}
projects / qemu.git / blobdiff