From 86b1cf322789b79c8ace977430ac6a443d491cc0 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 18 Jan 2021 13:34:47 +0100 Subject: block: Separate blk_is_writable() and blk_supports_write_perm() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, blk_is_read_only() tells whether a given BlockBackend can only be used in read-only mode because its root node is read-only. Some callers actually try to answer a slightly different question: Is the BlockBackend configured to be writable, by taking write permissions on the root node? This can differ, for example, for CD-ROM devices which don't take write permissions, but may be backed by a writable image file. scsi-cd allows write requests to the drive if blk_is_read_only() returns false. However, the write request will immediately run into an assertion failure because the write permission is missing. This patch introduces separate functions for both questions. blk_supports_write_perm() answers the question whether the block node/image file can support writable devices, whereas blk_is_writable() tells whether the BlockBackend is currently configured to be writable. All calls of blk_is_read_only() are converted to one of the two new functions. Fixes: https://bugs.launchpad.net/bugs/1906693 Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf Message-Id: <20210118123448.307825-2-kwolf@redhat.com> Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- hw/block/dataplane/xen-block.c | 2 +- hw/block/fdc.c | 9 +++++---- hw/block/m25p80.c | 6 +++--- hw/block/nand.c | 2 +- hw/block/nvme-ns.c | 7 ++++--- hw/block/onenand.c | 2 +- hw/block/pflash_cfi01.c | 2 +- hw/block/pflash_cfi02.c | 2 +- hw/block/swim.c | 6 +++--- hw/block/virtio-blk.c | 6 +++--- hw/block/xen-block.c | 2 +- 11 files changed, 24 insertions(+), 22 deletions(-) (limited to 'hw/block') diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c index 3675f8deaf..860787580a 100644 --- a/hw/block/dataplane/xen-block.c +++ b/hw/block/dataplane/xen-block.c @@ -168,7 +168,7 @@ static int xen_block_parse_request(XenBlockRequest *request) }; if (request->req.operation != BLKIF_OP_READ && - blk_is_read_only(dataplane->blk)) { + !blk_is_writable(dataplane->blk)) { error_report("error: write req for ro device"); goto err; } diff --git a/hw/block/fdc.c b/hw/block/fdc.c index 3636874432..292ea87805 100644 --- a/hw/block/fdc.c +++ b/hw/block/fdc.c @@ -444,7 +444,7 @@ static void fd_revalidate(FDrive *drv) FLOPPY_DPRINTF("revalidate\n"); if (drv->blk != NULL) { - drv->ro = blk_is_read_only(drv->blk); + drv->ro = !blk_is_writable(drv->blk); if (!blk_is_inserted(drv->blk)) { FLOPPY_DPRINTF("No disk in drive\n"); drv->disk = FLOPPY_DRIVE_TYPE_NONE; @@ -479,8 +479,8 @@ static void fd_change_cb(void *opaque, bool load, Error **errp) blk_set_perm(drive->blk, 0, BLK_PERM_ALL, &error_abort); } else { if (!blkconf_apply_backend_options(drive->conf, - blk_is_read_only(drive->blk), false, - errp)) { + !blk_supports_write_perm(drive->blk), + false, errp)) { return; } } @@ -553,7 +553,8 @@ static void floppy_drive_realize(DeviceState *qdev, Error **errp) * read-only node later */ read_only = true; } else { - read_only = !blk_bs(dev->conf.blk) || blk_is_read_only(dev->conf.blk); + read_only = !blk_bs(dev->conf.blk) || + !blk_supports_write_perm(dev->conf.blk); } if (!blkconf_blocksizes(&dev->conf, errp)) { diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c index b744a58d1c..0412d3e7f4 100644 --- a/hw/block/m25p80.c +++ b/hw/block/m25p80.c @@ -508,7 +508,7 @@ static void flash_sync_page(Flash *s, int page) { QEMUIOVector *iov; - if (!s->blk || blk_is_read_only(s->blk)) { + if (!s->blk || !blk_is_writable(s->blk)) { return; } @@ -524,7 +524,7 @@ static inline void flash_sync_area(Flash *s, int64_t off, int64_t len) { QEMUIOVector *iov; - if (!s->blk || blk_is_read_only(s->blk)) { + if (!s->blk || !blk_is_writable(s->blk)) { return; } @@ -1434,7 +1434,7 @@ static void m25p80_realize(SSIPeripheral *ss, Error **errp) if (s->blk) { uint64_t perm = BLK_PERM_CONSISTENT_READ | - (blk_is_read_only(s->blk) ? 0 : BLK_PERM_WRITE); + (blk_supports_write_perm(s->blk) ? BLK_PERM_WRITE : 0); ret = blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp); if (ret < 0) { return; diff --git a/hw/block/nand.c b/hw/block/nand.c index 913292ad1d..8bc80e3514 100644 --- a/hw/block/nand.c +++ b/hw/block/nand.c @@ -400,7 +400,7 @@ static void nand_realize(DeviceState *dev, Error **errp) pagesize = 1 << s->oob_shift; s->mem_oob = 1; if (s->blk) { - if (blk_is_read_only(s->blk)) { + if (!blk_supports_write_perm(s->blk)) { error_setg(errp, "Can't use a read-only drive"); return; } diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c index 31c80cdf5b..2670787d26 100644 --- a/hw/block/nvme-ns.c +++ b/hw/block/nvme-ns.c @@ -48,13 +48,14 @@ static void nvme_ns_init(NvmeNamespace *ns) static int nvme_ns_init_blk(NvmeCtrl *n, NvmeNamespace *ns, Error **errp) { + bool read_only; + if (!blkconf_blocksizes(&ns->blkconf, errp)) { return -1; } - if (!blkconf_apply_backend_options(&ns->blkconf, - blk_is_read_only(ns->blkconf.blk), - false, errp)) { + read_only = !blk_supports_write_perm(ns->blkconf.blk); + if (!blkconf_apply_backend_options(&ns->blkconf, read_only, false, errp)) { return -1; } diff --git a/hw/block/onenand.c b/hw/block/onenand.c index 579a73d7f7..afc0cd3a0f 100644 --- a/hw/block/onenand.c +++ b/hw/block/onenand.c @@ -797,7 +797,7 @@ static void onenand_realize(DeviceState *dev, Error **errp) s->image = memset(g_malloc(size + (size >> 5)), 0xff, size + (size >> 5)); } else { - if (blk_is_read_only(s->blk)) { + if (!blk_supports_write_perm(s->blk)) { error_setg(errp, "Can't use a read-only drive"); return; } diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c index ccf326793d..22287a1522 100644 --- a/hw/block/pflash_cfi01.c +++ b/hw/block/pflash_cfi01.c @@ -745,7 +745,7 @@ static void pflash_cfi01_realize(DeviceState *dev, Error **errp) if (pfl->blk) { uint64_t perm; - pfl->ro = blk_is_read_only(pfl->blk); + pfl->ro = !blk_supports_write_perm(pfl->blk); perm = BLK_PERM_CONSISTENT_READ | (pfl->ro ? 0 : BLK_PERM_WRITE); ret = blk_set_perm(pfl->blk, perm, BLK_PERM_ALL, errp); if (ret < 0) { diff --git a/hw/block/pflash_cfi02.c b/hw/block/pflash_cfi02.c index 2ad2f6baea..7962cff745 100644 --- a/hw/block/pflash_cfi02.c +++ b/hw/block/pflash_cfi02.c @@ -802,7 +802,7 @@ static void pflash_cfi02_realize(DeviceState *dev, Error **errp) if (pfl->blk) { uint64_t perm; - pfl->ro = blk_is_read_only(pfl->blk); + pfl->ro = !blk_supports_write_perm(pfl->blk); perm = BLK_PERM_CONSISTENT_READ | (pfl->ro ? 0 : BLK_PERM_WRITE); ret = blk_set_perm(pfl->blk, perm, BLK_PERM_ALL, errp); if (ret < 0) { diff --git a/hw/block/swim.c b/hw/block/swim.c index 20133a814c..509c2f4900 100644 --- a/hw/block/swim.c +++ b/hw/block/swim.c @@ -137,8 +137,8 @@ static void swim_change_cb(void *opaque, bool load, Error **errp) blk_set_perm(drive->blk, 0, BLK_PERM_ALL, &error_abort); } else { if (!blkconf_apply_backend_options(drive->conf, - blk_is_read_only(drive->blk), false, - errp)) { + !blk_supports_write_perm(drive->blk), + false, errp)) { return; } } @@ -210,7 +210,7 @@ static void swim_drive_realize(DeviceState *qdev, Error **errp) dev->conf.werror = BLOCKDEV_ON_ERROR_AUTO; if (!blkconf_apply_backend_options(&dev->conf, - blk_is_read_only(dev->conf.blk), + !blk_supports_write_perm(dev->conf.blk), false, errp)) { return; } diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index bac2d6fa2b..e8600b069d 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1021,7 +1021,7 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) { virtio_add_feature(&features, VIRTIO_BLK_F_WCE); } - if (blk_is_read_only(s->blk)) { + if (!blk_is_writable(s->blk)) { virtio_add_feature(&features, VIRTIO_BLK_F_RO); } if (s->conf.num_queues > 1) { @@ -1175,8 +1175,8 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) } if (!blkconf_apply_backend_options(&conf->conf, - blk_is_read_only(conf->conf.blk), true, - errp)) { + !blk_supports_write_perm(conf->conf.blk), + true, errp)) { return; } s->original_wce = blk_enable_write_cache(conf->conf.blk); diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index 718d886e5c..0e7d66c2a7 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -567,7 +567,7 @@ static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp) return; } - blockdev->info = blk_is_read_only(conf->blk) ? VDISK_READONLY : 0; + blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY; } static void xen_disk_class_init(ObjectClass *class, void *data) -- cgit v1.2.3