Am 22.08.2014 um 10:42 schrieb Kevin Wolf: > Am 22.08.2014 um 09:40 hat Peter Lieven geschrieben: >> Am 22.08.2014 um 09:35 schrieb Peter Lieven: >>> 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 <kw...@redhat.com> >>> Acked-by: Paolo Bonzini <pbonz...@redhat.com> >>> Reviewed-by: Benoit Canet <ben...@irqsave.net> >>> Reviewed-by: Eric Blake <ebl...@redhat.com> >>> --- >>> block/iscsi.c | 5 ++++- >>> 1 file changed, 4 insertions(+), 1 deletion(-) >>> >>> diff --git a/block/iscsi.c b/block/iscsi.c >>> index 84aa22a..06afa78 100644 >>> --- a/block/iscsi.c >>> +++ b/block/iscsi.c >>> @@ -893,7 +893,10 @@ 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); >> Unfortunately, I missed that one. The zeroblock is typicalls 512 Byte or 4K >> depending >> on the blocksize. > I don't remember the details, but I think when I went through all > drivers, I couldn't convince myself that a reasonable block size is > enforced somewhere. So I just went ahead and converted the call to be on > the safe side. It can never hurt anyway. > >> What is significantly larger is the allocationmap. It is typically created >> on iscsi_open, but is also recreated on iscsi_truncate. I don't have the >> context why this >> patch was introduced, but I would vote for introducing a bitmap_try_new and >> issue >> a warning if the allocation fails. The allocationmap is optional we can work >> without it. >> If the pointer is NULL its not used. > Right, that one I missed because it doesn't directly use g_malloc(). > > Your proposal sounds good to me. Are you going to prepare a patch?
will do. Peter