On Wed, Aug 12, 2026, 3:34 AM Stefan Hajnoczi <[email protected]> wrote:
> On Fri, Aug 07, 2026 at 04:25:14AM +0800, Zhang Chen wrote: > > Track the IOThreads used by a block export and identify the holder > > with the unique BlockExportOptions id. > > > > Acquire holder-aware references during export creation and release > > them on error or export deletion. Support both single- and > > multi-iothread exports. > > > > Signed-off-by: Zhang Chen <[email protected]> > > --- > > block/export/export.c | 79 +++++++++++++++++++++++++++++++++++++----- > > include/block/export.h | 6 ++++ > > 2 files changed, 76 insertions(+), 9 deletions(-) > > > > diff --git a/block/export/export.c b/block/export/export.c > > index b733f269f3..96d719418e 100644 > > --- a/block/export/export.c > > +++ b/block/export/export.c > > @@ -15,7 +15,6 @@ > > > > #include "block/block.h" > > #include "system/block-backend.h" > > -#include "system/iothread.h" > > #include "block/export.h" > > #include "block/fuse.h" > > #include "block/nbd.h" > > @@ -85,6 +84,8 @@ BlockExport *blk_exp_add(BlockExportOptions *export, > Error **errp) > > AioContext *ctx; > > AioContext **multithread_ctxs = NULL; > > size_t multithread_count = 0; > > + g_autofree IOThread **local_iothreads = NULL; > > + const char *holder_id = NULL; > > uint64_t perm; > > int ret; > > > > @@ -139,7 +140,16 @@ BlockExport *blk_exp_add(BlockExportOptions > *export, Error **errp) > > goto fail; > > } > > > > - new_ctx = iothread_get_aio_context(iothread); > > + holder_id = export->id; > > + const IOThreadHolder holder = { > > + .type = IO_THREAD_HOLDER_KIND_BLOCK_EXPORT, > > + .u.block_export.export_id = (char *)holder_id, > > Is this char * cast necessary since the holder variable is declared > const? > > > OK，will fix it in v12. Thanks Chen > > + }; > > + > > + new_ctx = iothread_ref_and_get_aio_context(iothread, &holder); > > + multithread_count = 1; > > + local_iothreads = g_new0(IOThread *, 1); > > + local_iothreads[0] = iothread; > > > > /* Ignore errors with fixed-iothread=false */ > > set_context_errp = fixed_iothread ? errp : NULL; > > @@ -163,8 +173,15 @@ BlockExport *blk_exp_add(BlockExportOptions > *export, Error **errp) > > return NULL; > > } > > > > + local_iothreads = g_new0(IOThread *, multithread_count); > > multithread_ctxs = g_new(AioContext *, multithread_count); > > i = 0; > > + holder_id = export->id; > > + const IOThreadHolder holder = { > > + .type = IO_THREAD_HOLDER_KIND_BLOCK_EXPORT, > > + .u.block_export.export_id = (char *)holder_id, > > Same here. > > > + }; > > + > > for (strList *e = iothread_list; e; e = e->next) { > > IOThread *iothread = iothread_by_id(e->value); > > > > @@ -172,7 +189,9 @@ BlockExport *blk_exp_add(BlockExportOptions *export, > Error **errp) > > error_setg(errp, "iothread \"%s\" not found", e->value); > > goto fail; > > } > > - multithread_ctxs[i++] = iothread_get_aio_context(iothread); > > + local_iothreads[i] = iothread; > > + multithread_ctxs[i++] = > iothread_ref_and_get_aio_context(iothread, > > + > &holder); > > } > > assert(i == multithread_count); > > } > > @@ -225,12 +244,15 @@ BlockExport *blk_exp_add(BlockExportOptions > *export, Error **errp) > > assert(drv->instance_size >= sizeof(BlockExport)); > > exp = g_malloc0(drv->instance_size); > > *exp = (BlockExport) { > > - .drv = drv, > > - .refcount = 1, > > - .user_owned = true, > > - .id = g_strdup(export->id), > > - .ctx = ctx, > > - .blk = blk, > > + .drv = drv, > > + .refcount = 1, > > + .user_owned = true, > > + .id = g_strdup(export->id), > > + .ctx = ctx, > > + .blk = blk, > > + .iothreads = g_steal_pointer(&local_iothreads), > > + .iothread_count = multithread_count, > > + .iothread_holder_id = g_strdup(holder_id), > > }; > > > > ret = drv->create(exp, export, multithread_ctxs, multithread_count, > errp); > > @@ -250,8 +272,32 @@ fail: > > blk_unref(blk); > > } > > if (exp) { > > + if (exp->iothreads) { > > + const IOThreadHolder holder = { > > + .type = IO_THREAD_HOLDER_KIND_BLOCK_EXPORT, > > + .u.block_export.export_id = exp->iothread_holder_id, > > + }; > > + for (size_t j = 0; j < exp->iothread_count; j++) { > > + if (exp->iothreads[j]) { > > + iothread_put_aio_context(exp->iothreads[j], > &holder); > > + } > > + } > > + g_free(exp->iothreads); > > + } > > + g_free(exp->iothread_holder_id); > > g_free(exp->id); > > g_free(exp); > > + } else if (local_iothreads) { > > + const IOThreadHolder holder = { > > + .type = IO_THREAD_HOLDER_KIND_BLOCK_EXPORT, > > + .u.block_export.export_id = (char *)holder_id, > > Same here. > > > + }; > > + > > + for (size_t j = 0; j < multithread_count; j++) { > > + if (local_iothreads[j]) { > > + iothread_put_aio_context(local_iothreads[j], &holder); > > + } > > + } > > } > > g_free(multithread_ctxs); > > return NULL; > > @@ -269,10 +315,25 @@ static void blk_exp_delete_bh(void *opaque) > > BlockExport *exp = opaque; > > > > assert(exp->refcount == 0); > > + > > QLIST_REMOVE(exp, next); > > exp->drv->delete(exp); > > blk_set_dev_ops(exp->blk, NULL, NULL); > > blk_unref(exp->blk); > > + > > + if (exp->iothreads) { > > + const IOThreadHolder holder = { > > + .type = IO_THREAD_HOLDER_KIND_BLOCK_EXPORT, > > + .u.block_export.export_id = exp->iothread_holder_id, > > + }; > > + > > + for (size_t i = 0; i < exp->iothread_count; i++) { > > + iothread_put_aio_context(exp->iothreads[i], &holder); > > + } > > + g_free(exp->iothreads); > > + } > > + > > + g_free(exp->iothread_holder_id); > > qapi_event_send_block_export_deleted(exp->id); > > g_free(exp->id); > > g_free(exp); > > diff --git a/include/block/export.h b/include/block/export.h > > index ca45da928c..a093dea0b6 100644 > > --- a/include/block/export.h > > +++ b/include/block/export.h > > @@ -16,6 +16,7 @@ > > > > #include "qapi/qapi-types-block-export.h" > > #include "qemu/queue.h" > > +#include "system/iothread.h" > > > > typedef struct BlockExport BlockExport; > > > > @@ -89,6 +90,11 @@ struct BlockExport { > > > > /* List entry for block_exports */ > > QLIST_ENTRY(BlockExport) next; > > + > > + /* The IOThreads utilized by this specific block export */ > > + IOThread **iothreads; > > + size_t iothread_count; > > + char *iothread_holder_id; > > }; > > > > BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp); > > -- > > 2.53.0 > > >
