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/sd/sd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'hw/sd/sd.c') diff --git a/hw/sd/sd.c b/hw/sd/sd.c index b3952514fe..8517dbce8b 100644 --- a/hw/sd/sd.c +++ b/hw/sd/sd.c @@ -567,7 +567,7 @@ static void sd_reset(DeviceState *dev) sd_set_sdstatus(sd); g_free(sd->wp_groups); - sd->wp_switch = sd->blk ? blk_is_read_only(sd->blk) : false; + sd->wp_switch = sd->blk ? !blk_is_writable(sd->blk) : false; sd->wpgrps_size = sect; sd->wp_groups = bitmap_new(sd->wpgrps_size); memset(sd->function_group, 0, sizeof(sd->function_group)); @@ -735,7 +735,7 @@ void sd_set_cb(SDState *sd, qemu_irq readonly, qemu_irq insert) { sd->readonly_cb = readonly; sd->inserted_cb = insert; - qemu_set_irq(readonly, sd->blk ? blk_is_read_only(sd->blk) : 0); + qemu_set_irq(readonly, sd->blk ? !blk_is_writable(sd->blk) : 0); qemu_set_irq(insert, sd->blk ? blk_is_inserted(sd->blk) : 0); } @@ -2131,7 +2131,7 @@ static void sd_realize(DeviceState *dev, Error **errp) if (sd->blk) { int64_t blk_size; - if (blk_is_read_only(sd->blk)) { + if (!blk_supports_write_perm(sd->blk)) { error_setg(errp, "Cannot use read-only drive as SD card"); return; } -- cgit 1.4.1