vhdx: Handle failure for potentially large allocations

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 <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
This commit is contained in:
Kevin Wolf 2014-05-20 13:55:50 +02:00
parent 17cce73578
commit a67e128a4f
2 changed files with 17 additions and 3 deletions

View File

@ -352,7 +352,12 @@ 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->file,
desc_sectors * VHDX_LOG_SECTOR_SIZE);
if (desc_entries == NULL) {
ret = -ENOMEM;
goto exit;
}
ret = vhdx_log_read_sectors(bs, log, &sectors_read, desc_entries,
desc_sectors, false);

View File

@ -958,7 +958,12 @@ 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->file, 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) {
goto fail;
@ -1587,7 +1592,11 @@ 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(length);
s->bat = g_try_malloc0(length);
if (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;