[Qemu-devel] [PATCH 07/20] iscsi: Handle failure for potentially large allocations

[Kevin Wolf]

Some code in the block layer makes potentially huge allocations. Failure
is not completely unexpected there, so avoid aborting qemu and handle
out-of-memory situations gracefully.

This patch addresses the allocations in the iscsi block driver.

Signed-off-by: Kevin Wolf <address@hidden>
---
 block/iscsi.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 52355b8..c047ca8 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -296,7 +296,10 @@ static int coroutine_fn iscsi_co_writev(BlockDriverState 
*bs,
         data = iov->iov[0].iov_base;
     } else {
         size_t size = MIN(nb_sectors * BDRV_SECTOR_SIZE, iov->size);
-        buf = g_malloc(size);
+        buf = g_try_malloc(size);
+        if (buf == NULL) {
+            return -ENOMEM;
+        }
         qemu_iovec_to_buf(iov, 0, buf, size);
         data = buf;
     }
@@ -550,7 +553,11 @@ static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState 
*bs,
 #else
             struct iovec *iov = (struct iovec *)acb->ioh->dxferp;
 
-            acb->buf = g_malloc(acb->ioh->dxfer_len);
+            acb->buf = g_try_malloc(acb->ioh->dxfer_len);
+            if (acb->buf == NULL) {
+                qemu_aio_release(acb);
+                return NULL;
+            }
             data.data = acb->buf;
             data.size = iov_to_buf(iov, acb->ioh->iovec_count, 0,
                                    acb->buf, acb->ioh->dxfer_len);
@@ -823,7 +830,10 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, 
int64_t sector_num,
     nb_blocks = sector_qemu2lun(nb_sectors, iscsilun);
 
     if (iscsilun->zeroblock == NULL) {
-        iscsilun->zeroblock = g_malloc0(iscsilun->block_size);
+        iscsilun->zeroblock = g_try_malloc0(iscsilun->block_size);
+        if (iscsilun->zeroblock == NULL) {
+            return -ENOMEM;
+        }
     }
 
     iscsi_co_init_iscsitask(iscsilun, &iTask);
-- 
1.8.3.1