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From: Christoph Hellwig <hch@lst.de>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] barriers: block layer preparations
Date: Tue, 5 May 2009 14:08:17 +0200	[thread overview]
Message-ID: <20090505120817.GA30721@lst.de> (raw)
In-Reply-To: <20090505120804.GA30651@lst.de>

Add a flag to BlockDriverState to advertise barriers support, and add a flags
argument to bdrv_aio_readv/writev to allow passing down the barrier flag.

Note that the flags argument to bdrv_aio_readv is for now actually superflous
because write barriers obviously only apply to writes.  I kept the read side
argument so the API is symmetric and we can easily add more flags to both
of them.


Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: qemu/block-qcow.c
===================================================================
--- qemu.orig/block-qcow.c	2009-04-26 16:38:30.509074899 +0200
+++ qemu/block-qcow.c	2009-05-05 11:29:11.545784130 +0200
@@ -587,7 +587,7 @@ static void qcow_aio_read_cb(void *opaqu
             acb->hd_iov.iov_len = acb->n * 512;
             qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
             acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
-                &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
+                &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb, 0);
             if (acb->hd_aiocb == NULL)
                 goto done;
         } else {
@@ -612,7 +612,7 @@ static void qcow_aio_read_cb(void *opaqu
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
         acb->hd_aiocb = bdrv_aio_readv(s->hd,
                             (acb->cluster_offset >> 9) + index_in_cluster,
-                            &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
+                            &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb, 0);
         if (acb->hd_aiocb == NULL)
             goto done;
     }
@@ -630,7 +630,7 @@ done:
 
 static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     QCowAIOCB *acb;
 
@@ -708,7 +708,7 @@ static void qcow_aio_write_cb(void *opaq
     acb->hd_aiocb = bdrv_aio_writev(s->hd,
                                     (cluster_offset >> 9) + index_in_cluster,
                                     &acb->hd_qiov, acb->n,
-                                    qcow_aio_write_cb, acb);
+                                    qcow_aio_write_cb, acb, 0);
     if (acb->hd_aiocb == NULL)
         goto done;
     return;
@@ -722,7 +722,7 @@ done:
 
 static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     BDRVQcowState *s = bs->opaque;
     QCowAIOCB *acb;
Index: qemu/block-qcow2.c
===================================================================
--- qemu.orig/block-qcow2.c	2009-04-26 16:47:40.682949219 +0200
+++ qemu/block-qcow2.c	2009-05-05 11:29:11.546784118 +0200
@@ -1349,7 +1349,7 @@ static void qcow_aio_read_cb(void *opaqu
                 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
                 acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
                                     &acb->hd_qiov, acb->n,
-				    qcow_aio_read_cb, acb);
+				    qcow_aio_read_cb, acb, 0);
                 if (acb->hd_aiocb == NULL)
                     goto done;
             } else {
@@ -1384,7 +1384,7 @@ static void qcow_aio_read_cb(void *opaqu
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
         acb->hd_aiocb = bdrv_aio_readv(s->hd,
                             (acb->cluster_offset >> 9) + index_in_cluster,
-                            &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
+                            &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb, 0);
         if (acb->hd_aiocb == NULL)
             goto done;
     }
@@ -1427,7 +1427,7 @@ static QCowAIOCB *qcow_aio_setup(BlockDr
 
 static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     QCowAIOCB *acb;
 
@@ -1498,7 +1498,7 @@ static void qcow_aio_write_cb(void *opaq
     acb->hd_aiocb = bdrv_aio_writev(s->hd,
                                     (acb->cluster_offset >> 9) + index_in_cluster,
                                     &acb->hd_qiov, acb->n,
-                                    qcow_aio_write_cb, acb);
+                                    qcow_aio_write_cb, acb, 2);
     if (acb->hd_aiocb == NULL)
         goto done;
 
@@ -1513,7 +1513,7 @@ done:
 
 static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     BDRVQcowState *s = bs->opaque;
     QCowAIOCB *acb;
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c	2009-04-26 16:38:30.513074989 +0200
+++ qemu/block.c	2009-05-05 11:29:11.547817490 +0200
@@ -59,10 +59,10 @@ typedef struct BlockDriverAIOCBSync {
 
 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags);
 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags);
 static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
                         uint8_t *buf, int nb_sectors);
@@ -1309,7 +1309,8 @@ char *bdrv_snapshot_dump(char *buf, int 
 
 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
                                  QEMUIOVector *qiov, int nb_sectors,
-                                 BlockDriverCompletionFunc *cb, void *opaque)
+                                 BlockDriverCompletionFunc *cb, void *opaque,
+                                 unsigned flags)
 {
     BlockDriver *drv = bs->drv;
     BlockDriverAIOCB *ret;
@@ -1320,7 +1321,7 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDr
         return NULL;
 
     ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
-                              cb, opaque);
+                              cb, opaque, flags);
 
     if (ret) {
 	/* Update stats even though technically transfer has not happened. */
@@ -1333,7 +1334,8 @@ BlockDriverAIOCB *bdrv_aio_readv(BlockDr
 
 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
                                   QEMUIOVector *qiov, int nb_sectors,
-                                  BlockDriverCompletionFunc *cb, void *opaque)
+                                  BlockDriverCompletionFunc *cb, void *opaque,
+                                  unsigned flags)
 {
     BlockDriver *drv = bs->drv;
     BlockDriverAIOCB *ret;
@@ -1346,7 +1348,7 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockD
         return NULL;
 
     ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
-                               cb, opaque);
+                               cb, opaque, flags);
 
     if (ret) {
 	/* Update stats even though technically transfer has not happened. */
@@ -1411,14 +1413,14 @@ static BlockDriverAIOCB *bdrv_aio_rw_vec
 
 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
 }
 
 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
 }
@@ -1454,7 +1456,7 @@ static int bdrv_read_em(BlockDriverState
     iov.iov_len = nb_sectors * 512;
     qemu_iovec_init_external(&qiov, &iov, 1);
     acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
-        bdrv_rw_em_cb, &async_ret);
+        bdrv_rw_em_cb, &async_ret, 0);
     if (acb == NULL)
         return -1;
 
@@ -1478,7 +1480,7 @@ static int bdrv_write_em(BlockDriverStat
     iov.iov_len = nb_sectors * 512;
     qemu_iovec_init_external(&qiov, &iov, 1);
     acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
-        bdrv_rw_em_cb, &async_ret);
+        bdrv_rw_em_cb, &async_ret, 0);
     if (acb == NULL)
         return -1;
     while (async_ret == NOT_DONE) {
Index: qemu/block.h
===================================================================
--- qemu.orig/block.h	2009-04-26 16:38:30.513074989 +0200
+++ qemu/block.h	2009-05-05 11:29:11.549784011 +0200
@@ -54,6 +54,12 @@ typedef struct QEMUSnapshotInfo {
 
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_CACHE_DEF)
 
+
+/*
+ * Flags for bdrv_aio_readv/bdrv_aio_writev.
+ */
+#define BDRV_IO_BARRIER    0x0001
+
 void bdrv_info(Monitor *mon);
 void bdrv_info_stats(Monitor *mon);
 
@@ -93,10 +99,12 @@ typedef void BlockDriverCompletionFunc(v
 
 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
                                  QEMUIOVector *iov, int nb_sectors,
-                                 BlockDriverCompletionFunc *cb, void *opaque);
+                                 BlockDriverCompletionFunc *cb, void *opaque,
+                                 unsigned flags);
 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
                                   QEMUIOVector *iov, int nb_sectors,
-                                  BlockDriverCompletionFunc *cb, void *opaque);
+                                  BlockDriverCompletionFunc *cb, void *opaque,
+                                  unsigned flags);
 void bdrv_aio_cancel(BlockDriverAIOCB *acb);
 
 /* sg packet commands */
Index: qemu/dma-helpers.c
===================================================================
--- qemu.orig/dma-helpers.c	2009-04-26 16:38:30.531074417 +0200
+++ qemu/dma-helpers.c	2009-05-05 11:29:11.550836309 +0200
@@ -120,10 +120,10 @@ static void dma_bdrv_cb(void *opaque, in
 
     if (dbs->is_write) {
         dbs->acb = bdrv_aio_writev(dbs->bs, dbs->sector_num, &dbs->iov,
-                                   dbs->iov.size / 512, dma_bdrv_cb, dbs);
+                                   dbs->iov.size / 512, dma_bdrv_cb, dbs, 0);
     } else {
         dbs->acb = bdrv_aio_readv(dbs->bs, dbs->sector_num, &dbs->iov,
-                                  dbs->iov.size / 512, dma_bdrv_cb, dbs);
+                                  dbs->iov.size / 512, dma_bdrv_cb, dbs, 0);
     }
     if (!dbs->acb) {
         dma_bdrv_unmap(dbs);
Index: qemu/hw/ide.c
===================================================================
--- qemu.orig/hw/ide.c	2009-05-04 17:02:14.367783478 +0200
+++ qemu/hw/ide.c	2009-05-05 11:29:11.552783415 +0200
@@ -1473,7 +1473,7 @@ static void ide_atapi_cmd_read_dma_cb(vo
     bm->iov.iov_len = n * 4 * 512;
     qemu_iovec_init_external(&bm->qiov, &bm->iov, 1);
     bm->aiocb = bdrv_aio_readv(s->bs, (int64_t)s->lba << 2, &bm->qiov,
-                               n * 4, ide_atapi_cmd_read_dma_cb, bm);
+                               n * 4, ide_atapi_cmd_read_dma_cb, bm, 0);
     if (!bm->aiocb) {
         /* Note: media not present is the most likely case */
         ide_atapi_cmd_error(s, SENSE_NOT_READY,
Index: qemu/hw/scsi-disk.c
===================================================================
--- qemu.orig/hw/scsi-disk.c	2009-04-26 16:38:30.592081973 +0200
+++ qemu/hw/scsi-disk.c	2009-05-05 11:29:11.554836260 +0200
@@ -210,7 +210,7 @@ static void scsi_read_data(SCSIDevice *d
     r->iov.iov_len = n * 512;
     qemu_iovec_init_external(&r->qiov, &r->iov, 1);
     r->aiocb = bdrv_aio_readv(s->bdrv, r->sector, &r->qiov, n,
-                              scsi_read_complete, r);
+                              scsi_read_complete, r, 0);
     if (r->aiocb == NULL)
         scsi_command_complete(r, STATUS_CHECK_CONDITION, SENSE_HARDWARE_ERROR);
     r->sector += n;
@@ -275,7 +275,7 @@ static void scsi_write_request(SCSIReque
     if (n) {
         qemu_iovec_init_external(&r->qiov, &r->iov, 1);
         r->aiocb = bdrv_aio_writev(s->bdrv, r->sector, &r->qiov, n,
-                                   scsi_write_complete, r);
+                                   scsi_write_complete, r, 0);
         if (r->aiocb == NULL)
             scsi_command_complete(r, STATUS_CHECK_CONDITION,
                                   SENSE_HARDWARE_ERROR);
Index: qemu/hw/virtio-blk.c
===================================================================
--- qemu.orig/hw/virtio-blk.c	2009-05-04 17:02:14.374784160 +0200
+++ qemu/hw/virtio-blk.c	2009-05-05 13:21:24.196784347 +0200
@@ -212,13 +212,13 @@ static void virtio_blk_handle_scsi(VirtI
 static void virtio_blk_handle_write(VirtIOBlockReq *req)
 {
     bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
-                    req->qiov.size / 512, virtio_blk_rw_complete, req);
+                    req->qiov.size / 512, virtio_blk_rw_complete, req, 0);
 }
 
 static void virtio_blk_handle_read(VirtIOBlockReq *req)
 {
     bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
-                   req->qiov.size / 512, virtio_blk_rw_complete, req);
+                   req->qiov.size / 512, virtio_blk_rw_complete, req, 0);
 }
 
 static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
Index: qemu/hw/xen_disk.c
===================================================================
--- qemu.orig/hw/xen_disk.c	2009-04-26 16:38:30.612075090 +0200
+++ qemu/hw/xen_disk.c	2009-05-05 11:29:11.556785880 +0200
@@ -397,14 +397,14 @@ static int ioreq_runio_qemu_aio(struct i
         ioreq->aio_inflight++;
         bdrv_aio_readv(blkdev->bs, ioreq->start / BLOCK_SIZE,
                        &ioreq->v, ioreq->v.size / BLOCK_SIZE,
-                       qemu_aio_complete, ioreq);
+                       qemu_aio_complete, ioreq, 0);
 	break;
     case BLKIF_OP_WRITE:
     case BLKIF_OP_WRITE_BARRIER:
         ioreq->aio_inflight++;
         bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE,
                         &ioreq->v, ioreq->v.size / BLOCK_SIZE,
-                        qemu_aio_complete, ioreq);
+                        qemu_aio_complete, ioreq, 0);
 	break;
     default:
 	/* unknown operation (shouldn't happen -- parse catches this) */
Index: qemu/qemu-io.c
===================================================================
--- qemu.orig/qemu-io.c	2009-05-04 17:02:14.381783935 +0200
+++ qemu/qemu-io.c	2009-05-05 11:31:57.159659916 +0200
@@ -148,7 +148,7 @@ static int do_aio_readv(QEMUIOVector *qi
 	int async_ret = NOT_DONE;
 
 	acb = bdrv_aio_readv(bs, offset >> 9, qiov, qiov->size >> 9,
-			     aio_rw_done, &async_ret);
+			     aio_rw_done, &async_ret, 0);
 	if (!acb)
 		return -EIO;
 
@@ -165,7 +165,7 @@ static int do_aio_writev(QEMUIOVector *q
 	int async_ret = NOT_DONE;
 
 	acb = bdrv_aio_writev(bs, offset >> 9, qiov, qiov->size >> 9,
-			      aio_rw_done, &async_ret);
+			      aio_rw_done, &async_ret, 0);
 	if (!acb)
 		return -EIO;
 
Index: qemu/block-raw-posix.c
===================================================================
--- qemu.orig/block-raw-posix.c	2009-04-28 11:42:09.257949541 +0200
+++ qemu/block-raw-posix.c	2009-05-05 13:21:23.136784385 +0200
@@ -654,7 +654,7 @@ static void raw_aio_remove(RawAIOCB *acb
 
 static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     RawAIOCB *acb;
 
@@ -670,7 +670,7 @@ static BlockDriverAIOCB *raw_aio_readv(B
 
 static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque)
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags)
 {
     RawAIOCB *acb;
 
Index: qemu/block_int.h
===================================================================
--- qemu.orig/block_int.h	2009-04-26 16:38:30.513074989 +0200
+++ qemu/block_int.h	2009-05-05 13:23:37.599695377 +0200
@@ -56,10 +56,10 @@ struct BlockDriver {
     /* aio */
     BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags);
     BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
-        BlockDriverCompletionFunc *cb, void *opaque);
+        BlockDriverCompletionFunc *cb, void *opaque, unsigned flags);
     void (*bdrv_aio_cancel)(BlockDriverAIOCB *acb);
     int aiocb_size;
 
@@ -117,6 +117,7 @@ struct BlockDriverState {
     int encrypted; /* if true, the media is encrypted */
     int valid_key; /* if true, a valid encryption key has been set */
     int sg;        /* if true, the device is a /dev/sg* */
+    int barrier_support;  /* if true, the device supports barrier requests */
     /* event callback when inserting/removing */
     void (*change_cb)(void *opaque);
     void *change_opaque;

  reply	other threads:[~2009-05-05 12:08 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-05 12:08 [Qemu-devel] [PATCH 0/3] write barrier support Christoph Hellwig
2009-05-05 12:08 ` Christoph Hellwig [this message]
2009-05-05 13:51   ` [Qemu-devel] barriers: block layer preparations Avi Kivity
2009-05-05 15:38     ` Jamie Lokier
2009-05-05 15:49       ` Avi Kivity
2009-05-05 16:00         ` Jamie Lokier
2009-05-05 20:57     ` Christoph Hellwig
2009-05-05 22:49       ` Jamie Lokier
2009-05-05 12:08 ` [Qemu-devel] [PATCH 2/3] barriers: block-raw-posix barrier support Christoph Hellwig
2009-05-05 12:33   ` Jamie Lokier
2009-05-05 13:29     ` Christoph Hellwig
2009-05-05 16:00       ` Jamie Lokier
2009-05-05 12:09 ` [Qemu-devel] [PATCH 3/3] barriers: virtio Christoph Hellwig
2009-05-05 13:53 ` [Qemu-devel] [PATCH 0/3] write barrier support Avi Kivity
2009-05-05 21:00   ` Christoph Hellwig

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