The Tuesday 03 Jun 2014 à 15:10:58 (+0200), Kevin Wolf wrote :
> 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 vhdx block driver.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
> ---
> block/vhdx-log.c | 6 +++++-
> block/vhdx.c | 12 ++++++++++--
> 2 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/block/vhdx-log.c b/block/vhdx-log.c
> index a77c040..3eb7e68 100644
> --- a/block/vhdx-log.c
> +++ b/block/vhdx-log.c
> @@ -349,7 +349,11 @@ static int vhdx_log_read_desc(BlockDriverState *bs,
> BDRVVHDXState *s,
> }
>
> desc_sectors = vhdx_compute_desc_sectors(hdr.descriptor_count);
> - desc_entries = qemu_blockalign(bs, desc_sectors * VHDX_LOG_SECTOR_SIZE);
> + desc_entries = qemu_try_blockalign(bs, desc_sectors *
> VHDX_LOG_SECTOR_SIZE);
> + if (desc_entries == NULL) {
> + ret = -ENOMEM;
> + goto exit;
> + }
>
> ret = vhdx_log_read_sectors(bs, log, §ors_read, desc_entries,
> desc_sectors, false);
> diff --git a/block/vhdx.c b/block/vhdx.c
> index 353c74d..0922f55 100644
> --- a/block/vhdx.c
> +++ b/block/vhdx.c
> @@ -950,7 +950,11 @@ static int vhdx_open(BlockDriverState *bs, QDict
> *options, int flags,
> }
>
> /* s->bat is freed in vhdx_close() */
> - s->bat = qemu_blockalign(bs, s->bat_rt.length);
> + s->bat = qemu_try_blockalign(bs, s->bat_rt.length);
> + if (s->bat == NULL) {
> + ret = -ENOMEM;
> + goto fail;
> + }
>
> ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length);
> if (ret < 0) {
> @@ -1579,7 +1583,11 @@ static int vhdx_create_bat(BlockDriverState *bs,
> BDRVVHDXState *s,
> use_zero_blocks ||
> bdrv_has_zero_init(bs) == 0) {
> /* for a fixed file, the default BAT entry is not zero */
> - s->bat = g_malloc0(rt_bat->length);
> + s->bat = g_try_malloc0(rt_bat->length);
> + if (rt_bat->length && s->bat != NULL) {
> + ret = -ENOMEM;
> + goto exit;
> + }
> block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT :
> PAYLOAD_BLOCK_NOT_PRESENT;
> block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;
> --
> 1.8.3.1
>
>
Reviewed-by: Benoit Canet <ben...@irqsave.net>