Merge remote-tracking branch 'bonzini/scsi-next' into staging

# By Peter Lieven (4) and Ronnie Sahlberg (1)
# Via Paolo Bonzini
* bonzini/scsi-next:
  iscsi: factor out sector conversions
  iscsi: assert that sectors are aligned to LUN blocksize
  iscsi: remove support for misaligned nb_sectors in aio_readv
  iscsi: fix -ENOSPC in iscsi_create()
  Fix iSCSI crash on SG_IO with an iovector

Message-id: 1374073524-8469-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 76 insertions, 28 deletions

diff --git a/block/iscsi.c b/block/iscsi.c
index 0bbf0b18b4..5f28c6a2ea 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -32,6 +32,7 @@
 #include "block/block_int.h"
 #include "trace.h"
 #include "block/scsi.h"
+#include "qemu/iov.h"
 
 #include <iscsi/iscsi.h>
 #include <iscsi/scsi-lowlevel.h>
@@ -61,8 +62,6 @@ typedef struct IscsiAIOCB {
     int status;
     int canceled;
     int retries;
-    size_t read_size;
-    size_t read_offset;
     int64_t sector_num;
     int nb_sectors;
 #ifdef __linux__
@@ -233,11 +232,28 @@ iscsi_aio_write16_cb(struct iscsi_context *iscsi, int status,
     iscsi_schedule_bh(acb);
 }
 
+static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
+{
+    return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
+}
+
 static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
 {
     return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
 }
 
+static bool is_request_lun_aligned(int64_t sector_num, int nb_sectors,
+                                      IscsiLun *iscsilun)
+{
+    if ((sector_num * BDRV_SECTOR_SIZE) % iscsilun->block_size ||
+        (nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size) {
+            error_report("iSCSI misaligned request: iscsilun->block_size %u, sector_num %ld, nb_sectors %d",
+                         iscsilun->block_size, sector_num, nb_sectors);
+            return 0;
+    }
+    return 1;
+}
+
 static int
 iscsi_aio_writev_acb(IscsiAIOCB *acb)
 {
@@ -285,7 +301,7 @@ iscsi_aio_writev_acb(IscsiAIOCB *acb)
     lba = sector_qemu2lun(acb->sector_num, acb->iscsilun);
     *(uint32_t *)&acb->task->cdb[2]  = htonl(lba >> 32);
     *(uint32_t *)&acb->task->cdb[6]  = htonl(lba & 0xffffffff);
-    num_sectors = size / acb->iscsilun->block_size;
+    num_sectors = sector_qemu2lun(acb->nb_sectors, acb->iscsilun);
     *(uint32_t *)&acb->task->cdb[10] = htonl(num_sectors);
     acb->task->expxferlen = size;
 
@@ -322,6 +338,10 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
     IscsiLun *iscsilun = bs->opaque;
     IscsiAIOCB *acb;
 
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        return NULL;
+    }
+
     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
     trace_iscsi_aio_writev(iscsilun->iscsi, sector_num, nb_sectors, opaque, acb);
 
@@ -379,6 +399,7 @@ static int
 iscsi_aio_readv_acb(IscsiAIOCB *acb)
 {
     struct iscsi_context *iscsi = acb->iscsilun->iscsi;
+    size_t size;
     uint64_t lba;
     uint32_t num_sectors;
     int ret;
@@ -391,20 +412,7 @@ iscsi_aio_readv_acb(IscsiAIOCB *acb)
     acb->status      = -EINPROGRESS;
     acb->buf         = NULL;
 
-    /* If LUN blocksize is bigger than BDRV_BLOCK_SIZE a read from QEMU
-     * may be misaligned to the LUN, so we may need to read some extra
-     * data.
-     */
-    acb->read_offset = 0;
-    if (acb->iscsilun->block_size > BDRV_SECTOR_SIZE) {
-        uint64_t bdrv_offset = BDRV_SECTOR_SIZE * acb->sector_num;
-
-        acb->read_offset  = bdrv_offset % acb->iscsilun->block_size;
-    }
-
-    num_sectors  = (acb->read_size + acb->iscsilun->block_size
-                    + acb->read_offset - 1)
-                    / acb->iscsilun->block_size;
+    size = acb->nb_sectors * BDRV_SECTOR_SIZE;
 
     acb->task = malloc(sizeof(struct scsi_task));
     if (acb->task == NULL) {
@@ -415,8 +423,9 @@ iscsi_aio_readv_acb(IscsiAIOCB *acb)
     memset(acb->task, 0, sizeof(struct scsi_task));
 
     acb->task->xfer_dir = SCSI_XFER_READ;
+    acb->task->expxferlen = size;
     lba = sector_qemu2lun(acb->sector_num, acb->iscsilun);
-    acb->task->expxferlen = acb->read_size;
+    num_sectors = sector_qemu2lun(acb->nb_sectors, acb->iscsilun);
 
     switch (acb->iscsilun->type) {
     case TYPE_DISK:
@@ -464,6 +473,10 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
     IscsiLun *iscsilun = bs->opaque;
     IscsiAIOCB *acb;
 
+    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
+        return NULL;
+    }
+
     acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
     trace_iscsi_aio_readv(iscsilun->iscsi, sector_num, nb_sectors, opaque, acb);
 
@@ -471,7 +484,6 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
     acb->sector_num  = sector_num;
     acb->iscsilun    = iscsilun;
     acb->qiov        = qiov;
-    acb->read_size   = BDRV_SECTOR_SIZE * (size_t)acb->nb_sectors;
     acb->retries     = ISCSI_CMD_RETRIES;
 
     if (iscsi_aio_readv_acb(acb) != 0) {
@@ -651,6 +663,9 @@ iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
 {
     IscsiAIOCB *acb = opaque;
 
+    g_free(acb->buf);
+    acb->buf = NULL;
+
     if (acb->canceled != 0) {
         return;
     }
@@ -727,14 +742,30 @@ static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
     memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
     acb->task->expxferlen = acb->ioh->dxfer_len;
 
+    data.size = 0;
     if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
-        data.data = acb->ioh->dxferp;
-        data.size = acb->ioh->dxfer_len;
+        if (acb->ioh->iovec_count == 0) {
+            data.data = acb->ioh->dxferp;
+            data.size = acb->ioh->dxfer_len;
+        } else {
+#if defined(LIBISCSI_FEATURE_IOVECTOR)
+            scsi_task_set_iov_out(acb->task,
+                                 (struct scsi_iovec *) acb->ioh->dxferp,
+                                 acb->ioh->iovec_count);
+#else
+            struct iovec *iov = (struct iovec *)acb->ioh->dxferp;
+
+            acb->buf = g_malloc(acb->ioh->dxfer_len);
+            data.data = acb->buf;
+            data.size = iov_to_buf(iov, acb->ioh->iovec_count, 0,
+                                   acb->buf, acb->ioh->dxfer_len);
+#endif
+        }
     }
+
     if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
                                  iscsi_aio_ioctl_cb,
-                                 (acb->task->xfer_dir == SCSI_XFER_WRITE) ?
-                                     &data : NULL,
+                                 (data.size > 0) ? &data : NULL,
                                  acb) != 0) {
         scsi_free_scsi_task(acb->task);
         qemu_aio_release(acb);
@@ -743,9 +774,26 @@ static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
 
     /* tell libiscsi to read straight into the buffer we got from ioctl */
     if (acb->task->xfer_dir == SCSI_XFER_READ) {
-        scsi_task_add_data_in_buffer(acb->task,
-                                     acb->ioh->dxfer_len,
-                                     acb->ioh->dxferp);
+        if (acb->ioh->iovec_count == 0) {
+            scsi_task_add_data_in_buffer(acb->task,
+                                         acb->ioh->dxfer_len,
+                                         acb->ioh->dxferp);
+        } else {
+#if defined(LIBISCSI_FEATURE_IOVECTOR)
+            scsi_task_set_iov_in(acb->task,
+                                 (struct scsi_iovec *) acb->ioh->dxferp,
+                                 acb->ioh->iovec_count);
+#else
+            int i;
+            for (i = 0; i < acb->ioh->iovec_count; i++) {
+                struct iovec *iov = (struct iovec *)acb->ioh->dxferp;
+
+                scsi_task_add_data_in_buffer(acb->task,
+                    iov[i].iov_len,
+                    iov[i].iov_base);
+            }
+#endif
+        }
     }
 
     iscsi_set_events(iscsilun);
@@ -1118,8 +1166,7 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags)
     if ((ret = iscsi_readcapacity_sync(iscsilun)) != 0) {
         goto out;
     }
-    bs->total_sectors    = iscsilun->num_blocks *
-                           iscsilun->block_size / BDRV_SECTOR_SIZE ;
+    bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
 
     /* Medium changer or tape. We dont have any emulation for this so this must
      * be sg ioctl compatible. We force it to be sg, otherwise qemu will try
@@ -1235,6 +1282,7 @@ static int iscsi_create(const char *filename, QEMUOptionParameter *options)
     }
     if (bs.total_sectors < total_size) {
         ret = -ENOSPC;
+        goto out;
     }
 
     ret = 0;