Message ID | 1401287873-25805-11-git-send-email-kwolf@redhat.com |
---|---|
State | New |
Headers | show |
The Wednesday 28 May 2014 à 16:37:43 (+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 qcow1 block driver. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > block/qcow.c | 33 ++++++++++++++++++++++++++------- > 1 file changed, 26 insertions(+), 7 deletions(-) > > diff --git a/block/qcow.c b/block/qcow.c > index 7fd57d7..31db585 100644 > --- a/block/qcow.c > +++ b/block/qcow.c > @@ -182,7 +182,12 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > } > > s->l1_table_offset = header.l1_table_offset; > - s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t)); > + s->l1_table = g_try_malloc(s->l1_size * sizeof(uint64_t)); > + if (s->l1_table == NULL) { > + error_setg(errp, "Could not allocate memory for L1 table"); > + ret = -ENOMEM; > + goto fail; > + } > > ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, > s->l1_size * sizeof(uint64_t)); > @@ -193,8 +198,16 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > for(i = 0;i < s->l1_size; i++) { > be64_to_cpus(&s->l1_table[i]); > } > - /* alloc L2 cache */ > - s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); > + > + /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */ > + s->l2_cache = > + qemu_try_blockalign(bs->file, > + s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); > + if (s->l2_cache == NULL) { > + error_setg(errp, "Could not allocate L2 table cache"); > + ret = -ENOMEM; > + goto fail; > + } > s->cluster_cache = g_malloc(s->cluster_size); > s->cluster_data = g_malloc(s->cluster_size); > s->cluster_cache_offset = -1; > @@ -226,7 +239,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > > fail: > g_free(s->l1_table); > - g_free(s->l2_cache); > + qemu_vfree(s->l2_cache); > g_free(s->cluster_cache); > g_free(s->cluster_data); > return ret; > @@ -517,7 +530,10 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, > void *orig_buf; > > if (qiov->niov > 1) { > - buf = orig_buf = qemu_blockalign(bs, qiov->size); > + buf = orig_buf = qemu_try_blockalign(bs, qiov->size); What if qiov->size == 0 ? (posix_memalign will return NULL) > + if (buf == NULL) { > + return -ENOMEM; > + } > } else { > orig_buf = NULL; > buf = (uint8_t *)qiov->iov->iov_base; > @@ -619,7 +635,10 @@ static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, > s->cluster_cache_offset = -1; /* disable compressed cache */ > > if (qiov->niov > 1) { > - buf = orig_buf = qemu_blockalign(bs, qiov->size); > + buf = orig_buf = qemu_try_blockalign(bs, qiov->size); Same ? > + if (buf == NULL) { > + return -ENOMEM; > + } > qemu_iovec_to_buf(qiov, 0, buf, qiov->size); > } else { > orig_buf = NULL; > @@ -685,7 +704,7 @@ static void qcow_close(BlockDriverState *bs) > BDRVQcowState *s = bs->opaque; > > g_free(s->l1_table); > - g_free(s->l2_cache); > + qemu_vfree(s->l2_cache); > g_free(s->cluster_cache); > g_free(s->cluster_data); > > -- > 1.8.3.1 > >
Am 30.05.2014 um 14:43 hat Benoît Canet geschrieben: > The Wednesday 28 May 2014 à 16:37:43 (+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 qcow1 block driver. > > > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> > > --- > > block/qcow.c | 33 ++++++++++++++++++++++++++------- > > 1 file changed, 26 insertions(+), 7 deletions(-) > > > > diff --git a/block/qcow.c b/block/qcow.c > > index 7fd57d7..31db585 100644 > > --- a/block/qcow.c > > +++ b/block/qcow.c > > @@ -182,7 +182,12 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > > } > > > > s->l1_table_offset = header.l1_table_offset; > > - s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t)); > > + s->l1_table = g_try_malloc(s->l1_size * sizeof(uint64_t)); > > + if (s->l1_table == NULL) { > > + error_setg(errp, "Could not allocate memory for L1 table"); > > + ret = -ENOMEM; > > + goto fail; > > + } > > > > ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, > > s->l1_size * sizeof(uint64_t)); > > @@ -193,8 +198,16 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > > for(i = 0;i < s->l1_size; i++) { > > be64_to_cpus(&s->l1_table[i]); > > } > > - /* alloc L2 cache */ > > - s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); > > + > > + /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */ > > + s->l2_cache = > > + qemu_try_blockalign(bs->file, > > + s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); > > + if (s->l2_cache == NULL) { > > + error_setg(errp, "Could not allocate L2 table cache"); > > + ret = -ENOMEM; > > + goto fail; > > + } > > s->cluster_cache = g_malloc(s->cluster_size); > > s->cluster_data = g_malloc(s->cluster_size); > > s->cluster_cache_offset = -1; > > @@ -226,7 +239,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > > > > fail: > > g_free(s->l1_table); > > - g_free(s->l2_cache); > > + qemu_vfree(s->l2_cache); > > g_free(s->cluster_cache); > > g_free(s->cluster_data); > > return ret; > > @@ -517,7 +530,10 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, > > void *orig_buf; > > > > if (qiov->niov > 1) { > > - buf = orig_buf = qemu_blockalign(bs, qiov->size); > > + buf = orig_buf = qemu_try_blockalign(bs, qiov->size); > What if qiov->size == 0 ? (posix_memalign will return NULL) If you send a request with niov > 1, but size == 0, you just get what you deserve. ;-) Changed qemu_try_blockalign() semantics will handle this one in v3. Kevin
diff --git a/block/qcow.c b/block/qcow.c index 7fd57d7..31db585 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -182,7 +182,12 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, } s->l1_table_offset = header.l1_table_offset; - s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t)); + s->l1_table = g_try_malloc(s->l1_size * sizeof(uint64_t)); + if (s->l1_table == NULL) { + error_setg(errp, "Could not allocate memory for L1 table"); + ret = -ENOMEM; + goto fail; + } ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)); @@ -193,8 +198,16 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, for(i = 0;i < s->l1_size; i++) { be64_to_cpus(&s->l1_table[i]); } - /* alloc L2 cache */ - s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); + + /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */ + s->l2_cache = + qemu_try_blockalign(bs->file, + s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); + if (s->l2_cache == NULL) { + error_setg(errp, "Could not allocate L2 table cache"); + ret = -ENOMEM; + goto fail; + } s->cluster_cache = g_malloc(s->cluster_size); s->cluster_data = g_malloc(s->cluster_size); s->cluster_cache_offset = -1; @@ -226,7 +239,7 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, fail: g_free(s->l1_table); - g_free(s->l2_cache); + qemu_vfree(s->l2_cache); g_free(s->cluster_cache); g_free(s->cluster_data); return ret; @@ -517,7 +530,10 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, void *orig_buf; if (qiov->niov > 1) { - buf = orig_buf = qemu_blockalign(bs, qiov->size); + buf = orig_buf = qemu_try_blockalign(bs, qiov->size); + if (buf == NULL) { + return -ENOMEM; + } } else { orig_buf = NULL; buf = (uint8_t *)qiov->iov->iov_base; @@ -619,7 +635,10 @@ static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, s->cluster_cache_offset = -1; /* disable compressed cache */ if (qiov->niov > 1) { - buf = orig_buf = qemu_blockalign(bs, qiov->size); + buf = orig_buf = qemu_try_blockalign(bs, qiov->size); + if (buf == NULL) { + return -ENOMEM; + } qemu_iovec_to_buf(qiov, 0, buf, qiov->size); } else { orig_buf = NULL; @@ -685,7 +704,7 @@ static void qcow_close(BlockDriverState *bs) BDRVQcowState *s = bs->opaque; g_free(s->l1_table); - g_free(s->l2_cache); + qemu_vfree(s->l2_cache); g_free(s->cluster_cache); g_free(s->cluster_data);