The Tuesday 03 Jun 2014 à 15:10:57 (+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 vdi block driver.
>
> Signed-off-by: Kevin Wolf <kw...@redhat.com>
> Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
> ---
> block/vdi.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/block/vdi.c b/block/vdi.c
> index 27737af..1f76441 100644
> --- a/block/vdi.c
> +++ b/block/vdi.c
> @@ -293,7 +293,12 @@ static int vdi_check(BlockDriverState *bs,
> BdrvCheckResult *res,
> return -ENOTSUP;
> }
>
> - bmap = g_malloc(s->header.blocks_in_image * sizeof(uint32_t));
> + bmap = g_try_malloc(s->header.blocks_in_image * sizeof(uint32_t));
> + if (s->header.blocks_in_image && bmap == NULL) {
> + res->check_errors++;
> + return -ENOMEM;
> + }
> +
> memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t));
>
> /* Check block map and value of blocks_allocated. */
> @@ -472,7 +477,12 @@ static int vdi_open(BlockDriverState *bs, QDict
> *options, int flags,
>
> bmap_size = header.blocks_in_image * sizeof(uint32_t);
> bmap_size = (bmap_size + SECTOR_SIZE - 1) / SECTOR_SIZE;
> - s->bmap = g_malloc(bmap_size * SECTOR_SIZE);
> + s->bmap = qemu_try_blockalign(bs->file, bmap_size * SECTOR_SIZE);
> + if (s->bmap == NULL) {
> + ret = -ENOMEM;
> + goto fail;
> + }
> +
> ret = bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size);
> if (ret < 0) {
> goto fail_free_bmap;
> @@ -487,7 +497,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options,
> int flags,
> return 0;
>
> fail_free_bmap:
> - g_free(s->bmap);
> + qemu_vfree(s->bmap);
>
> fail:
> return ret;
> @@ -760,7 +770,11 @@ static int vdi_create(const char *filename,
> QEMUOptionParameter *options,
> }
>
> if (bmap_size > 0) {
> - uint32_t *bmap = g_malloc0(bmap_size);
> + uint32_t *bmap = g_try_malloc0(bmap_size);
> + if (bmap == NULL) {
> + result = -ENOMEM;
> + goto close_and_exit;
> + }
> for (i = 0; i < blocks; i++) {
> if (image_type == VDI_TYPE_STATIC) {
> bmap[i] = i;
> @@ -796,7 +810,7 @@ static void vdi_close(BlockDriverState *bs)
> {
> BDRVVdiState *s = bs->opaque;
>
> - g_free(s->bmap);
> + qemu_vfree(s->bmap);
>
> migrate_del_blocker(s->migration_blocker);
> error_free(s->migration_blocker);
> --
> 1.8.3.1
>
>
Reviewed-by: Benoit Canet <ben...@irqsave.net>
