[PATCH v2 4/5] block: use blk_get_max_ioctl_transfer for SCSI passthrough

[Maxim Levitsky <mlevitsk@redhat.com>]

Switch file-posix to expose only the max_ioctl_transfer limit.

Let the iscsi driver work as it did before since it is bound by the transfer
limit in both regular read/write and in SCSI passthrough case.

Switch the scsi-disk and scsi-block drivers to read the SG max transfer limits
using the new blk_get_max_ioctl_transfer interface.


Fixes: 867eccfed8 ("file-posix: Use max transfer length/segment count only for SCSI passthrough")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 block/file-posix.c     | 4 ++--
 block/iscsi.c          | 1 +
 hw/scsi/scsi-generic.c | 4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 10ebc4c5b7..0a94211847 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1284,12 +1284,12 @@ static void hdev_refresh_limits(BlockDriverState *bs, Error **errp)
                        get_max_transfer_length(s->fd);
 
     if (ret > 0 && ret <= BDRV_REQUEST_MAX_BYTES) {
-        bs->bl.max_transfer = pow2floor(ret);
+        bs->bl.max_ioctl_transfer = pow2floor(ret);
     }
 
     ret = bs->sg ? sg_get_max_segments(s->fd) : get_max_segments(s->fd);
     if (ret > 0) {
-        bs->bl.max_transfer = MIN_NON_ZERO(bs->bl.max_transfer,
+        bs->bl.max_ioctl_transfer = MIN_NON_ZERO(bs->bl.max_ioctl_transfer,
                                            ret * qemu_real_host_page_size);
     }
 
diff --git a/block/iscsi.c b/block/iscsi.c
index e30a7e3606..3685da2971 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -2065,6 +2065,7 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
 
     if (max_xfer_len * block_size < INT_MAX) {
         bs->bl.max_transfer = max_xfer_len * iscsilun->block_size;
+        bs->bl.max_ioctl_transfer = bs->bl.max_transfer;
     }
 
     if (iscsilun->lbp.lbpu) {
diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
index 2cb23ca891..6df67bf889 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -167,7 +167,7 @@ static void scsi_handle_inquiry_reply(SCSIGenericReq *r, SCSIDevice *s)
         page = r->req.cmd.buf[2];
         if (page == 0xb0) {
             uint32_t max_transfer =
-                blk_get_max_transfer(s->conf.blk) / s->blocksize;
+                blk_get_max_ioctl_transfer(s->conf.blk) / s->blocksize;
 
             assert(max_transfer);
             stl_be_p(&r->buf[8], max_transfer);
@@ -210,7 +210,7 @@ static int scsi_generic_emulate_block_limits(SCSIGenericReq *r, SCSIDevice *s)
     uint8_t buf[64];
 
     SCSIBlockLimits bl = {
-        .max_io_sectors = blk_get_max_transfer(s->conf.blk) / s->blocksize
+        .max_io_sectors = blk_get_max_ioctl_transfer(s->conf.blk) / s->blocksize
     };
 
     memset(r->buf, 0, r->buflen);
-- 
2.26.2