From 067179868ec8cd467d9810143339e882cb60e388 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 27 Oct 2023 17:53:11 +0200 Subject: [PATCH] block: Mark bdrv_has_zero_init() and callers GRAPH_RDLOCK This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_has_zero_init() need to hold a reader lock for the graph because it calls bdrv_filter_bs(), which accesses bs->file/backing. Signed-off-by: Kevin Wolf Message-ID: <20231027155333.420094-3-kwolf@redhat.com> Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block.c | 2 +- block/qcow2.c | 3 ++- block/raw-format.c | 2 +- block/vdi.c | 2 +- block/vhdx.c | 13 +++++++++---- block/vmdk.c | 2 +- block/vpc.c | 2 +- blockdev.c | 2 ++ include/block/block-global-state.h | 2 +- include/block/block_int-common.h | 2 +- qemu-img.c | 2 ++ 11 files changed, 22 insertions(+), 12 deletions(-) diff --git a/block.c b/block.c index a527aa1a4c..1171f47570 100644 --- a/block.c +++ b/block.c @@ -6587,7 +6587,7 @@ int bdrv_has_zero_init_1(BlockDriverState *bs) return 1; } -int bdrv_has_zero_init(BlockDriverState *bs) +int coroutine_mixed_fn bdrv_has_zero_init(BlockDriverState *bs) { BlockDriverState *filtered; GLOBAL_STATE_CODE(); diff --git a/block/qcow2.c b/block/qcow2.c index aa01d9e7b5..a1443a31aa 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -5302,7 +5302,8 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs, return spec_info; } -static int coroutine_mixed_fn qcow2_has_zero_init(BlockDriverState *bs) +static int coroutine_mixed_fn GRAPH_RDLOCK +qcow2_has_zero_init(BlockDriverState *bs) { BDRVQcow2State *s = bs->opaque; bool preallocated; diff --git a/block/raw-format.c b/block/raw-format.c index 3fb77b0097..8ca74c1cf3 100644 --- a/block/raw-format.c +++ b/block/raw-format.c @@ -452,7 +452,7 @@ raw_co_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) return bdrv_co_ioctl(bs->file->bs, req, buf); } -static int raw_has_zero_init(BlockDriverState *bs) +static int GRAPH_RDLOCK raw_has_zero_init(BlockDriverState *bs) { return bdrv_has_zero_init(bs->file->bs); } diff --git a/block/vdi.c b/block/vdi.c index 7cfd12b50d..8e144ce523 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -990,7 +990,7 @@ static void vdi_close(BlockDriverState *bs) migrate_del_blocker(&s->migration_blocker); } -static int vdi_has_zero_init(BlockDriverState *bs) +static int GRAPH_RDLOCK vdi_has_zero_init(BlockDriverState *bs) { BDRVVdiState *s = bs->opaque; diff --git a/block/vhdx.c b/block/vhdx.c index a9d08742f9..e136ba1ae1 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -1695,7 +1695,7 @@ exit: * Fixed images: default state of the BAT is fully populated, with * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. */ -static int coroutine_fn +static int coroutine_fn GRAPH_UNLOCKED vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, uint64_t image_size, VHDXImageType type, bool use_zero_blocks, uint64_t file_offset, @@ -1708,6 +1708,7 @@ vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, uint64_t unused; int block_state; VHDXSectorInfo sinfo; + bool has_zero_init; assert(s->bat == NULL); @@ -1737,9 +1738,13 @@ vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, goto exit; } + bdrv_graph_co_rdlock(); + has_zero_init = bdrv_has_zero_init(blk_bs(blk)); + bdrv_graph_co_rdunlock(); + if (type == VHDX_TYPE_FIXED || use_zero_blocks || - bdrv_has_zero_init(blk_bs(blk)) == 0) { + has_zero_init == 0) { /* for a fixed file, the default BAT entry is not zero */ s->bat = g_try_malloc0(length); if (length && s->bat == NULL) { @@ -1782,7 +1787,7 @@ exit: * to create the BAT itself, we will also cause the BAT to be * created. */ -static int coroutine_fn +static int coroutine_fn GRAPH_UNLOCKED vhdx_create_new_region_table(BlockBackend *blk, uint64_t image_size, uint32_t block_size, uint32_t sector_size, uint32_t log_size, bool use_zero_blocks, @@ -2173,7 +2178,7 @@ static int coroutine_fn vhdx_co_check(BlockDriverState *bs, return 0; } -static int vhdx_has_zero_init(BlockDriverState *bs) +static int GRAPH_RDLOCK vhdx_has_zero_init(BlockDriverState *bs) { BDRVVHDXState *s = bs->opaque; int state; diff --git a/block/vmdk.c b/block/vmdk.c index 85864b8045..91ed7a8d93 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -2894,7 +2894,7 @@ vmdk_co_get_allocated_file_size(BlockDriverState *bs) return ret; } -static int vmdk_has_zero_init(BlockDriverState *bs) +static int GRAPH_RDLOCK vmdk_has_zero_init(BlockDriverState *bs) { int i; BDRVVmdkState *s = bs->opaque; diff --git a/block/vpc.c b/block/vpc.c index aa1a48ae0e..483775103c 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -1170,7 +1170,7 @@ fail: } -static int vpc_has_zero_init(BlockDriverState *bs) +static int GRAPH_RDLOCK vpc_has_zero_init(BlockDriverState *bs) { BDRVVPCState *s = bs->opaque; diff --git a/blockdev.c b/blockdev.c index e9b7e38dc4..148df99e00 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3156,9 +3156,11 @@ void qmp_drive_mirror(DriveMirror *arg, Error **errp) return; } + bdrv_graph_rdlock_main_loop(); zero_target = (arg->sync == MIRROR_SYNC_MODE_FULL && (arg->mode == NEW_IMAGE_MODE_EXISTING || !bdrv_has_zero_init(target_bs))); + bdrv_graph_rdunlock_main_loop(); /* Honor bdrv_try_change_aio_context() context acquisition requirements. */ diff --git a/include/block/block-global-state.h b/include/block/block-global-state.h index fca0a40dbd..3ae468ea15 100644 --- a/include/block/block-global-state.h +++ b/include/block/block-global-state.h @@ -189,7 +189,7 @@ void bdrv_drain_all(void); void bdrv_aio_cancel(BlockAIOCB *acb); int bdrv_has_zero_init_1(BlockDriverState *bs); -int bdrv_has_zero_init(BlockDriverState *bs); +int coroutine_mixed_fn GRAPH_RDLOCK bdrv_has_zero_init(BlockDriverState *bs); BlockDriverState *bdrv_find_node(const char *node_name); BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp); XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp); diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 8abdd2724b..c0db862de7 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -349,7 +349,7 @@ struct BlockDriver { * Returns 1 if newly created images are guaranteed to contain only * zeros, 0 otherwise. */ - int (*bdrv_has_zero_init)(BlockDriverState *bs); + int GRAPH_RDLOCK_PTR (*bdrv_has_zero_init)(BlockDriverState *bs); /* * Remove fd handlers, timers, and other event loop callbacks so the event diff --git a/qemu-img.c b/qemu-img.c index 369c2e8ddf..c061fd0634 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2099,7 +2099,9 @@ static int convert_do_copy(ImgConvertState *s) /* Check whether we have zero initialisation or can get it efficiently */ if (!s->has_zero_init && s->target_is_new && s->min_sparse && !s->target_has_backing) { + bdrv_graph_rdlock_main_loop(); s->has_zero_init = bdrv_has_zero_init(blk_bs(s->target)); + bdrv_graph_rdunlock_main_loop(); } /* Allocate buffer for copied data. For compressed images, only one cluster